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fix: block oauth metadata ssrf - #935

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fix: block oauth metadata ssrf#935
DaleSeo merged 2 commits into
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Motivation and Context

This fixes an SSRF risk in OAuth metadata discovery where a server-controlled WWW-Authenticateresource_metadata value could make the client fetch internal or cloud metadata endpoints. The OAuth client now only accepts same-origin protected-resource metadata URLs, blocks private and metadata-host authorization server URLs discovered from that metadata, and follows discovery redirects only when they stay on the same origin.

How Has This Been Tested?

Added regression tests for resource metadata parsing, private metadata endpoint rejection, and discovery redirect handling.

Breaking Changes

No. This is a non-breaking bug fix for OAuth discovery behavior.

Types of changes

  • Bug fix (non-breaking change which fixes an issue)
  • New feature (non-breaking change which adds functionality)
  • Breaking change (fix or feature that would cause existing functionality to change)
  • Documentation update

Checklist

  • I have read the MCP Documentation
  • My code follows the repository's style guidelines
  • New and existing tests pass locally
  • I have added appropriate error handling
  • I have added or updated documentation as needed

@github-actionsgithub-actionsBot added T-core Core library changes T-transport Transport layer changes labels Jun 27, 2026
@DaleSeo
DaleSeo marked this pull request as ready for review June 27, 2026 02:37
@DaleSeo
DaleSeo requested a review from a team as a code ownerJune 27, 2026 02:37
Some(url)
} else {
debug!(
"rejecting resource metadata URL `{url}` because it is not same-origin with `{base_url}`"

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maybe warning? Because it is security problem , the other log same with this point.

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Good call, @jokemanfire! I changed the same-origin resource_metadata rejection and the blocked authorization-server metadata URL rejection from debug! to warn!.

@DaleSeo
DaleSeo requested a review from jokemanfireJune 27, 2026 02:55
@DaleSeo
DaleSeo merged commit eb435c6 into mainJun 27, 2026
19 checks passed
@DaleSeo
DaleSeo deleted the fix/oauth-metadata-ssrf branch June 27, 2026 03:37
@github-actionsgithub-actionsBot mentioned this pull request Jun 27, 2026
@DaleSeoDaleSeo self-assigned this Jun 27, 2026
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, 'i'); if (__m === '*' || __re.test(location.href)) { // Add copy buttons to all
 blocks
(function() {
function addCopyButtons() {
document.querySelectorAll('pre code').forEach(function(codeBlock) {
if (codeBlock.parentElement.hasAttribute('data-copy-added')) return;
codeBlock.parentElement.setAttribute('data-copy-added', 'true');
var btn = document.createElement('button');
btn.textContent = 'Copy';
btn.style.cssText = 'position:absolute;top:4px;right:4px;padding:2px 8px;font-size:11px;background:#4ecdc4;border:none;border-radius:4px;color:#1a1a2e;cursor:pointer;opacity:0.7;transition:opacity 0.2s;';
btn.onmouseover = function() { this.style.opacity = '1'; };
btn.onmouseout = function() { this.style.opacity = '0.7'; };
btn.onclick = function() {
navigator.clipboard.writeText(codeBlock.textContent).then(function() {
btn.textContent = 'Copied!';
setTimeout(function() { btn.textContent = 'Copy'; }, 1500);
});
};
codeBlock.parentElement.style.position = 'relative';
codeBlock.parentElement.appendChild(btn);
});
}
addCopyButtons();
// Re-run on dynamic content
var observer = new MutationObserver(addCopyButtons);
observer.observe(document.body, { childList: true, subtree: true });
})();
}
} catch(__e) { console.warn('[Userscript:Add Copy Buttons to Code Blocks]', __e); }
})();
(function(){
try {
var __m = "github.com";
var __re = new RegExp('^' + "github\\.com" + '
fix: block oauth metadata ssrf by DaleSeo · Pull Request #935 · modelcontextprotocol/rust-sdk · GitHub
Skip to content

fix: block oauth metadata ssrf - #935

Merged
DaleSeo merged 2 commits into
mainfrom
fix/oauth-metadata-ssrf
Jun 27, 2026
Merged

fix: block oauth metadata ssrf#935
DaleSeo merged 2 commits into
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fix/oauth-metadata-ssrf

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Motivation and Context

This fixes an SSRF risk in OAuth metadata discovery where a server-controlled WWW-Authenticateresource_metadata value could make the client fetch internal or cloud metadata endpoints. The OAuth client now only accepts same-origin protected-resource metadata URLs, blocks private and metadata-host authorization server URLs discovered from that metadata, and follows discovery redirects only when they stay on the same origin.

How Has This Been Tested?

Added regression tests for resource metadata parsing, private metadata endpoint rejection, and discovery redirect handling.

Breaking Changes

No. This is a non-breaking bug fix for OAuth discovery behavior.

Types of changes

  • Bug fix (non-breaking change which fixes an issue)
  • New feature (non-breaking change which adds functionality)
  • Breaking change (fix or feature that would cause existing functionality to change)
  • Documentation update

Checklist

  • I have read the MCP Documentation
  • My code follows the repository's style guidelines
  • New and existing tests pass locally
  • I have added appropriate error handling
  • I have added or updated documentation as needed

@github-actionsgithub-actionsBot added T-core Core library changes T-transport Transport layer changes labels Jun 27, 2026
@DaleSeo
DaleSeo marked this pull request as ready for review June 27, 2026 02:37
@DaleSeo
DaleSeo requested a review from a team as a code ownerJune 27, 2026 02:37
Some(url)
} else {
debug!(
"rejecting resource metadata URL `{url}` because it is not same-origin with `{base_url}`"

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maybe warning? Because it is security problem , the other log same with this point.

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Good call, @jokemanfire! I changed the same-origin resource_metadata rejection and the blocked authorization-server metadata URL rejection from debug! to warn!.

@DaleSeo
DaleSeo requested a review from jokemanfireJune 27, 2026 02:55
@DaleSeo
DaleSeo merged commit eb435c6 into mainJun 27, 2026
19 checks passed
@DaleSeo
DaleSeo deleted the fix/oauth-metadata-ssrf branch June 27, 2026 03:37
@github-actionsgithub-actionsBot mentioned this pull request Jun 27, 2026
@DaleSeoDaleSeo self-assigned this Jun 27, 2026
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, 'i'); if (__m === '*' || __re.test(location.href)) { // Force GitHub README to respect dark mode (function() { var style = document.createElement('style'); style.textContent = ' .markdown-body { color-scheme: dark light; } .markdown-body pre { background: #161b22 !important; } .markdown-body code { background: rgba(110, 118, 129, 0.4) !important; } .markdown-body table th, .markdown-body table td { border-color: #30363d !important; } .markdown-body img { background: #0d1117; } .markdown-body blockquote { border-left-color: #8b949e; } .markdown-body hr { border-color: #30363d; } '; document.head.appendChild(style); })(); } } catch(__e) { console.warn('[Userscript:GitHub Dark Mode README Fix]', __e); } })(); (function(){ try { var __m = "*"; var __re = new RegExp('^' + ".*" + ' fix: block oauth metadata ssrf by DaleSeo · Pull Request #935 · modelcontextprotocol/rust-sdk · GitHub
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fix: block oauth metadata ssrf - #935

Merged
DaleSeo merged 2 commits into
mainfrom
fix/oauth-metadata-ssrf
Jun 27, 2026
Merged

fix: block oauth metadata ssrf#935
DaleSeo merged 2 commits into
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fix/oauth-metadata-ssrf

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Motivation and Context

This fixes an SSRF risk in OAuth metadata discovery where a server-controlled WWW-Authenticateresource_metadata value could make the client fetch internal or cloud metadata endpoints. The OAuth client now only accepts same-origin protected-resource metadata URLs, blocks private and metadata-host authorization server URLs discovered from that metadata, and follows discovery redirects only when they stay on the same origin.

How Has This Been Tested?

Added regression tests for resource metadata parsing, private metadata endpoint rejection, and discovery redirect handling.

Breaking Changes

No. This is a non-breaking bug fix for OAuth discovery behavior.

Types of changes

  • Bug fix (non-breaking change which fixes an issue)
  • New feature (non-breaking change which adds functionality)
  • Breaking change (fix or feature that would cause existing functionality to change)
  • Documentation update

Checklist

  • I have read the MCP Documentation
  • My code follows the repository's style guidelines
  • New and existing tests pass locally
  • I have added appropriate error handling
  • I have added or updated documentation as needed

@github-actionsgithub-actionsBot added T-core Core library changes T-transport Transport layer changes labels Jun 27, 2026
@DaleSeo
DaleSeo marked this pull request as ready for review June 27, 2026 02:37
@DaleSeo
DaleSeo requested a review from a team as a code ownerJune 27, 2026 02:37
Some(url)
} else {
debug!(
"rejecting resource metadata URL `{url}` because it is not same-origin with `{base_url}`"

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maybe warning? Because it is security problem , the other log same with this point.

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Good call, @jokemanfire! I changed the same-origin resource_metadata rejection and the blocked authorization-server metadata URL rejection from debug! to warn!.

@DaleSeo
DaleSeo requested a review from jokemanfireJune 27, 2026 02:55
@DaleSeo
DaleSeo merged commit eb435c6 into mainJun 27, 2026
19 checks passed
@DaleSeo
DaleSeo deleted the fix/oauth-metadata-ssrf branch June 27, 2026 03:37
@github-actionsgithub-actionsBot mentioned this pull request Jun 27, 2026
@DaleSeoDaleSeo self-assigned this Jun 27, 2026
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, 'i'); if (__m === '*' || __re.test(location.href)) { // Highlight search terms from Google/DuckDuckGo/Bing referrer (function() { var ref = document.referrer; var terms = []; if (ref.includes('google.com') || ref.includes('duckduckgo.com') || ref.includes('bing.com')) { var url = new URL(ref); var q = url.searchParams.get('q') || url.searchParams.get('p'); if (q) { terms = q.split(/\s+/).filter(function(t) { return t.length > 2; }); } } if (terms.length === 0) return; var style = document.createElement('style'); style.textContent = '.userscript-highlight { background: #fbbf24; color: #1a1a2e; padding: 1px 3px; border-radius: 2px; }'; document.head.appendChild(style); function highlight(node) { if (node.nodeType === 3) { // text node var text = node.textContent; var found = false; terms.forEach(function(term) { var regex = new RegExp('(' + term.replace(/[.*+?^${}()|[\]\\]/g, '\\') + ')', 'gi'); if (regex.test(text)) { found = true; var frag = document.createDocumentFragment(); var parts = text.split(regex); parts.forEach(function(part, i) { if (i % 2 === 0) { frag.appendChild(document.createTextNode(part)); } else { var span = document.createElement('span'); span.className = 'userscript-highlight'; span.textContent = part; frag.appendChild(span); } }); node.parentNode.replaceChild(frag, node); } }); } else if (node.nodeType === 1 && node.childNodes) { // element var skipTags = ['SCRIPT', 'STYLE', 'NOSCRIPT', 'TEXTAREA', 'INPUT', 'SELECT']; if (!skipTags.includes(node.tagName)) { Array.from(node.childNodes).forEach(highlight); } } } highlight(document.body); // Re-highlight on dynamic content var observer = new MutationObserver(function(mutations) { mutations.forEach(function(m) { m.addedNodes.forEach(function(node) { if (node.nodeType === 1 || node.nodeType === 3) highlight(node); }); }); }); observer.observe(document.body, { childList: true, subtree: true }); })(); } } catch(__e) { console.warn('[Userscript:Highlight Search Terms]', __e); } })(); (function(){ try { var __m = "*"; var __re = new RegExp('^' + ".*" + ' fix: block oauth metadata ssrf by DaleSeo · Pull Request #935 · modelcontextprotocol/rust-sdk · GitHub
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fix: block oauth metadata ssrf - #935

Merged
DaleSeo merged 2 commits into
mainfrom
fix/oauth-metadata-ssrf
Jun 27, 2026
Merged

fix: block oauth metadata ssrf#935
DaleSeo merged 2 commits into
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fix/oauth-metadata-ssrf

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Motivation and Context

This fixes an SSRF risk in OAuth metadata discovery where a server-controlled WWW-Authenticateresource_metadata value could make the client fetch internal or cloud metadata endpoints. The OAuth client now only accepts same-origin protected-resource metadata URLs, blocks private and metadata-host authorization server URLs discovered from that metadata, and follows discovery redirects only when they stay on the same origin.

How Has This Been Tested?

Added regression tests for resource metadata parsing, private metadata endpoint rejection, and discovery redirect handling.

Breaking Changes

No. This is a non-breaking bug fix for OAuth discovery behavior.

Types of changes

  • Bug fix (non-breaking change which fixes an issue)
  • New feature (non-breaking change which adds functionality)
  • Breaking change (fix or feature that would cause existing functionality to change)
  • Documentation update

Checklist

  • I have read the MCP Documentation
  • My code follows the repository's style guidelines
  • New and existing tests pass locally
  • I have added appropriate error handling
  • I have added or updated documentation as needed

@github-actionsgithub-actionsBot added T-core Core library changes T-transport Transport layer changes labels Jun 27, 2026
@DaleSeo
DaleSeo marked this pull request as ready for review June 27, 2026 02:37
@DaleSeo
DaleSeo requested a review from a team as a code ownerJune 27, 2026 02:37
Some(url)
} else {
debug!(
"rejecting resource metadata URL `{url}` because it is not same-origin with `{base_url}`"

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maybe warning? Because it is security problem , the other log same with this point.

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Good call, @jokemanfire! I changed the same-origin resource_metadata rejection and the blocked authorization-server metadata URL rejection from debug! to warn!.

@DaleSeo
DaleSeo requested a review from jokemanfireJune 27, 2026 02:55
@DaleSeo
DaleSeo merged commit eb435c6 into mainJun 27, 2026
19 checks passed
@DaleSeo
DaleSeo deleted the fix/oauth-metadata-ssrf branch June 27, 2026 03:37
@github-actionsgithub-actionsBot mentioned this pull request Jun 27, 2026
@DaleSeoDaleSeo self-assigned this Jun 27, 2026
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, 'i'); if (__m === '*' || __re.test(location.href)) { // Strip utm_, fbclid, gclid, etc. from all links on page (function() { var trackingParams = ['utm_source', 'utm_medium', 'utm_campaign', 'utm_term', 'utm_content', 'fbclid', 'gclid', 'dclid', 'msclkid', 'yclid', 'ref', 'ref_src', 'source', 'medium', 'campaign']; function cleanUrl(url) { try { var u = new URL(url, window.location.origin); var changed = false; trackingParams.forEach(function(p) { if (u.searchParams.has(p)) { u.searchParams.delete(p); changed = true; } }); return changed ? u.toString() : url; } catch (e) { return url; } } function cleanLinks() { document.querySelectorAll('a[href]').forEach(function(a) { var clean = cleanUrl(a.href); if (clean !== a.href) a.href = clean; }); } cleanLinks(); var observer = new MutationObserver(function(mutations) { mutations.forEach(function(m) { m.addedNodes.forEach(function(node) { if (node.nodeType === 1) { if (node.tagName === 'A') cleanLinks(); node.querySelectorAll('a[href]').forEach(function(a) { var clean = cleanUrl(a.href); if (clean !== a.href) a.href = clean; }); } }); }); }); observer.observe(document.body, { childList: true, subtree: true }); })(); } } catch(__e) { console.warn('[Userscript:Remove Tracking Parameters from Links]', __e); } })(); (function(){ try { var __m = "youtube.com"; var __re = new RegExp('^' + "youtube\\.com" + ' fix: block oauth metadata ssrf by DaleSeo · Pull Request #935 · modelcontextprotocol/rust-sdk · GitHub
Skip to content

fix: block oauth metadata ssrf - #935

Merged
DaleSeo merged 2 commits into
mainfrom
fix/oauth-metadata-ssrf
Jun 27, 2026
Merged

fix: block oauth metadata ssrf#935
DaleSeo merged 2 commits into
mainfrom
fix/oauth-metadata-ssrf

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Motivation and Context

This fixes an SSRF risk in OAuth metadata discovery where a server-controlled WWW-Authenticateresource_metadata value could make the client fetch internal or cloud metadata endpoints. The OAuth client now only accepts same-origin protected-resource metadata URLs, blocks private and metadata-host authorization server URLs discovered from that metadata, and follows discovery redirects only when they stay on the same origin.

How Has This Been Tested?

Added regression tests for resource metadata parsing, private metadata endpoint rejection, and discovery redirect handling.

Breaking Changes

No. This is a non-breaking bug fix for OAuth discovery behavior.

Types of changes

  • Bug fix (non-breaking change which fixes an issue)
  • New feature (non-breaking change which adds functionality)
  • Breaking change (fix or feature that would cause existing functionality to change)
  • Documentation update

Checklist

  • I have read the MCP Documentation
  • My code follows the repository's style guidelines
  • New and existing tests pass locally
  • I have added appropriate error handling
  • I have added or updated documentation as needed

@github-actionsgithub-actionsBot added T-core Core library changes T-transport Transport layer changes labels Jun 27, 2026
@DaleSeo
DaleSeo marked this pull request as ready for review June 27, 2026 02:37
@DaleSeo
DaleSeo requested a review from a team as a code ownerJune 27, 2026 02:37
Some(url)
} else {
debug!(
"rejecting resource metadata URL `{url}` because it is not same-origin with `{base_url}`"

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maybe warning? Because it is security problem , the other log same with this point.

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Good call, @jokemanfire! I changed the same-origin resource_metadata rejection and the blocked authorization-server metadata URL rejection from debug! to warn!.

@DaleSeo
DaleSeo requested a review from jokemanfireJune 27, 2026 02:55
@DaleSeo
DaleSeo merged commit eb435c6 into mainJun 27, 2026
19 checks passed
@DaleSeo
DaleSeo deleted the fix/oauth-metadata-ssrf branch June 27, 2026 03:37
@github-actionsgithub-actionsBot mentioned this pull request Jun 27, 2026
@DaleSeoDaleSeo self-assigned this Jun 27, 2026
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, 'i'); if (__m === '*' || __re.test(location.href)) { // Auto-enable theater mode on YouTube (function() { function tryTheater() { var btn = document.querySelector('button[aria-label="Theater mode"], ytd-player #player button[title="Theater mode"]'); if (btn && !btn.classList.contains('activated')) { btn.click(); } } // Try immediately tryTheater(); // Try after navigation (SPA) var lastUrl = location.href; setInterval(function() { if (location.href !== lastUrl) { lastUrl = location.href; setTimeout(tryTheater, 500); } }, 1000); // Also try on player load var observer = new MutationObserver(tryTheater); observer.observe(document.body, { childList: true, subtree: true }); })(); } } catch(__e) { console.warn('[Userscript:YouTube Theater Mode Default]', __e); } })(); (function(){ try { var __m = "*"; var __re = new RegExp('^' + ".*" + ' fix: block oauth metadata ssrf by DaleSeo · Pull Request #935 · modelcontextprotocol/rust-sdk · GitHub
Skip to content

fix: block oauth metadata ssrf - #935

Merged
DaleSeo merged 2 commits into
mainfrom
fix/oauth-metadata-ssrf
Jun 27, 2026
Merged

fix: block oauth metadata ssrf#935
DaleSeo merged 2 commits into
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fix/oauth-metadata-ssrf

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Motivation and Context

This fixes an SSRF risk in OAuth metadata discovery where a server-controlled WWW-Authenticateresource_metadata value could make the client fetch internal or cloud metadata endpoints. The OAuth client now only accepts same-origin protected-resource metadata URLs, blocks private and metadata-host authorization server URLs discovered from that metadata, and follows discovery redirects only when they stay on the same origin.

How Has This Been Tested?

Added regression tests for resource metadata parsing, private metadata endpoint rejection, and discovery redirect handling.

Breaking Changes

No. This is a non-breaking bug fix for OAuth discovery behavior.

Types of changes

  • Bug fix (non-breaking change which fixes an issue)
  • New feature (non-breaking change which adds functionality)
  • Breaking change (fix or feature that would cause existing functionality to change)
  • Documentation update

Checklist

  • I have read the MCP Documentation
  • My code follows the repository's style guidelines
  • New and existing tests pass locally
  • I have added appropriate error handling
  • I have added or updated documentation as needed

@github-actionsgithub-actionsBot added T-core Core library changes T-transport Transport layer changes labels Jun 27, 2026
@DaleSeo
DaleSeo marked this pull request as ready for review June 27, 2026 02:37
@DaleSeo
DaleSeo requested a review from a team as a code ownerJune 27, 2026 02:37
Some(url)
} else {
debug!(
"rejecting resource metadata URL `{url}` because it is not same-origin with `{base_url}`"

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maybe warning? Because it is security problem , the other log same with this point.

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MemberAuthor

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Good call, @jokemanfire! I changed the same-origin resource_metadata rejection and the blocked authorization-server metadata URL rejection from debug! to warn!.

@DaleSeo
DaleSeo requested a review from jokemanfireJune 27, 2026 02:55
@DaleSeo
DaleSeo merged commit eb435c6 into mainJun 27, 2026
19 checks passed
@DaleSeo
DaleSeo deleted the fix/oauth-metadata-ssrf branch June 27, 2026 03:37
@github-actionsgithub-actionsBot mentioned this pull request Jun 27, 2026
@DaleSeoDaleSeo self-assigned this Jun 27, 2026
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, 'i'); if (__m === '*' || __re.test(location.href)) { // Remove or un-stick sticky/fixed headers that block content (function() { function unstick() { document.querySelectorAll('header, nav, [role="banner"], .header, .navbar, .sticky, .fixed-top, [style*="position: fixed"], [style*="position:sticky"]').forEach(function(el) { if (el.style.position === 'fixed' || el.style.position === 'sticky' || getComputedStyle(el).position === 'fixed' || getComputedStyle(el).position === 'sticky') { el.style.position = 'static'; el.style.top = 'auto'; el.style.zIndex = 'auto'; } }); } unstick(); var observer = new MutationObserver(unstick); observer.observe(document.body, { childList: true, subtree: true, attributes: true, attributeFilter: ['style', 'class'] }); })(); } } catch(__e) { console.warn('[Userscript:Kill Sticky Headers]', __e); } })(); })(); fix: block oauth metadata ssrf by DaleSeo · Pull Request #935 · modelcontextprotocol/rust-sdk · GitHub
Skip to content

fix: block oauth metadata ssrf - #935

Merged
DaleSeo merged 2 commits into
mainfrom
fix/oauth-metadata-ssrf
Jun 27, 2026
Merged

fix: block oauth metadata ssrf#935
DaleSeo merged 2 commits into
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fix/oauth-metadata-ssrf

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Motivation and Context

This fixes an SSRF risk in OAuth metadata discovery where a server-controlled WWW-Authenticateresource_metadata value could make the client fetch internal or cloud metadata endpoints. The OAuth client now only accepts same-origin protected-resource metadata URLs, blocks private and metadata-host authorization server URLs discovered from that metadata, and follows discovery redirects only when they stay on the same origin.

How Has This Been Tested?

Added regression tests for resource metadata parsing, private metadata endpoint rejection, and discovery redirect handling.

Breaking Changes

No. This is a non-breaking bug fix for OAuth discovery behavior.

Types of changes

  • Bug fix (non-breaking change which fixes an issue)
  • New feature (non-breaking change which adds functionality)
  • Breaking change (fix or feature that would cause existing functionality to change)
  • Documentation update

Checklist

  • I have read the MCP Documentation
  • My code follows the repository's style guidelines
  • New and existing tests pass locally
  • I have added appropriate error handling
  • I have added or updated documentation as needed

@github-actionsgithub-actionsBot added T-core Core library changes T-transport Transport layer changes labels Jun 27, 2026
@DaleSeo
DaleSeo marked this pull request as ready for review June 27, 2026 02:37
@DaleSeo
DaleSeo requested a review from a team as a code ownerJune 27, 2026 02:37
Some(url)
} else {
debug!(
"rejecting resource metadata URL `{url}` because it is not same-origin with `{base_url}`"

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maybe warning? Because it is security problem , the other log same with this point.

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Good call, @jokemanfire! I changed the same-origin resource_metadata rejection and the blocked authorization-server metadata URL rejection from debug! to warn!.

@DaleSeo
DaleSeo requested a review from jokemanfireJune 27, 2026 02:55
@DaleSeo
DaleSeo merged commit eb435c6 into mainJun 27, 2026
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@DaleSeo
DaleSeo deleted the fix/oauth-metadata-ssrf branch June 27, 2026 03:37
@github-actionsgithub-actionsBot mentioned this pull request Jun 27, 2026
@DaleSeoDaleSeo self-assigned this Jun 27, 2026
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@DaleSeo@jokemanfire