{"items":[{"id":"NVI-00008944","kind":"vulnerability","title":"mcp-sanitizer: URL sanitizer allows localhost/IPv6 loopback SSRF bypass via explicit port or bracketed IPv6","revision":2,"unknowns":["Customer inventory, deployment, reachability and exploitation have not been inspected."],"lifecycle":"active","identifiers":["GHSA-4mfg-r38w-w8fg"],"plain_summary":"GitHub lists this reviewed advisory for mcp-sanitizer. Published version ranges and source prerequisites are shown below; this is not an inspection of a visitor’s application.","review_status":"source_listed","control_topics":[],"public_actions":[{"summary":"Identify the exact component and deployed version, examine the linked publisher’s conditions, and retain evidence of any mitigation.","source_ids":["sr-4117e4afc898dfaa87cdac36cba1a9c4"],"action_type":"investigate","limitations":"Confirm current vendor support, compatibility and deployment evidence. This report has not tested a fix in your system.","current_supported_target":null},{"summary":"The original advisory lists fixed boundaries 1.4.0 for mcp-sanitizer. Confirm the publisher’s latest guidance.","source_ids":["sr-f9f735f5c3b145d6eefe2353433a253f"],"action_type":"vendor_patch","limitations":"Confirm current vendor support, compatibility and deployment evidence. This report has not tested a fix in your system.","current_supported_target":null}],"schema_version":"1.1.0","source_metrics":[{"kind":"CVSS","as_of":"2026-10-28T19:51:40.000Z","value":"8.2 high","meaning":"GitHub source severity; exploitability and local consequence require separate evidence.","source_id":"sr-4117e4afc898dfaa87cdac36cba1a9c4"}],"why_it_matters":"Published affected context helps an owner decide what evidence to gather. This report has not examined your application.","related_sources":[{"id":"sr-4117e4afc898dfaa87cdac36cba1a9c4","url":"https://github.com/advisories/GHSA-4mfg-r38w-w8fg","basis":"vendor_advisory","notes":"GitHub Advisory Database; CC-BY-4.0. Each advisory links its original attribution. Null normalizes fields.","title":"GHSA-4mfg-r38w-w8fg","publisher":"GitHub Advisory Database","observed_at":"2026-10-31T21:56:36.327Z"},{"id":"sr-f9f735f5c3b145d6eefe2353433a253f","url":"https://github.com/advisories/GHSA-4mfg-r38w-w8fg","basis":"vendor_advisory","notes":"GitHub-origin advisory, CC-BY-4.0; OSV is an aggregate copy, not independent corroboration.","title":"GHSA-4mfg-r38w-w8fg","publisher":"GitHub Advisory Database via OSV","observed_at":"2026-11-01T22:54:30.549Z"}],"affected_context":[{"certainty":"source_listed","source_ids":["sr-4117e4afc898dfaa87cdac36cba1a9c4"],"technology":"mcp-sanitizer","known_exclusions":[],"conditions_summary":"## URL sanitizer allows localhost/IPv6 loopback SSRF bypass via explicit port or bracketed IPv6\n\n### Summary\n\n`mcp-sanitizer` v1.3.3 fails to block Server-Side Request Forgery (SSRF) targets when a `localhost` URL includes an explicit port (e.g., `http://localhost:8080/`) or when an IPv6 loopback/link-local address is expressed in bracketed notation (e.g., `http://[::1]:8080/`, `http://[fe80::1]:8080/`). Because the library is explicitly designed to gate MCP tool parameters such as `web_fetch` and `web_scraper` before outbound HTTP requests are made, a bypass here directly enables an attacker-controlled URL to reach internal services, leaking their responses.\n\n### Details\n\nThe vulnerability exists in `src/utils/validation-utils.js` inside the `validateURLLocation()` function that is called by `_secureSanitizeURL()` in `src/sanitizer/mcp-sanitizer.js:698`.\n\n**Bug 1 — Port-guarded localhost check (line 274–276):**\n\n```js\n// src/utils/validation-utils.js:274-276\nif ((hostname === 'localhost' || hostname === '127.0.0.1' || hostname === '::1') && !parsedUrl.port) {\n  throw new Error('URL points to localhost without explicit port');\n}\n```\n\nThe `&& !parsedUrl.port` guard means that any lo","public_affected_ranges":["< 1.4.0"]},{"certainty":"source_listed","source_ids":["sr-f9f735f5c3b145d6eefe2353433a253f"],"technology":"mcp-sanitizer","known_exclusions":[],"conditions_summary":"## URL sanitizer allows localhost/IPv6 loopback SSRF bypass via explicit port or bracketed IPv6\n\n### Summary\n\n`mcp-sanitizer` v1.3.3 fails to block Server-Side Request Forgery (SSRF) targets when a `localhost` URL includes an explicit port (e.g., `http://localhost:8080/`) or when an IPv6 loopback/link-local address is expressed in bracketed notation (e.g., `http://[::1]:8080/`, `http://[fe80::1]:8080/`). Because the library is explicitly designed to gate MCP tool parameters such as `web_fetch` and `web_scraper` before outbound HTTP requests are made, a bypass here directly enables an attacker-controlled URL to reach internal services, leaking their responses.\n\n### Details\n\nThe vulnerability exists in `src/utils/validation-utils.js` inside the `validateURLLocation()` function that is called by `_secureSanitizeURL()` in `src/sanitizer/mcp-sanitizer.js:698`.\n\n**Bug 1 — Port-guarded localhost check (line 274–276):**\n\n```js\n// src/utils/validation-utils.js:274-276\nif ((hostname === 'localhost' || hostname === '127.0.0.1' || hostname === '::1') && !parsedUrl.port) {\n  throw new Error('URL points to localhost without explicit port');\n}\n```\n\nThe `&& !parsedUrl.port` guard means that any lo","public_affected_ranges":["SEMVER: introduced 0; fixed 1.4.0"]}],"null_published_at":"2026-11-02T20:21:10.350Z","source_updated_at":"2026-10-28T19:51:40.000Z","source_disclosed_at":"2026-10-28T19:51:39.000Z","is_synthetic_fixture":false,"null_last_reviewed_at":null,"public_change_summary":"Source facts changed; compare the preserved prior revision.","null_first_observed_at":"2026-10-31T21:56:36.327Z"},{"id":"NVI-00008944","kind":"vulnerability","title":"mcp-sanitizer: URL sanitizer allows localhost/IPv6 loopback SSRF bypass via explicit port or bracketed IPv6","revision":1,"unknowns":["Customer inventory, deployment, reachability and exploitation have not been inspected."],"lifecycle":"active","identifiers":["GHSA-4mfg-r38w-w8fg"],"plain_summary":"GitHub lists this reviewed advisory for mcp-sanitizer. Published version ranges and source prerequisites are shown below; this is not an inspection of a visitor’s application.","review_status":"source_listed","control_topics":[],"public_actions":[{"summary":"Identify the exact component and deployed version, examine the linked publisher’s conditions, and retain evidence of any mitigation.","source_ids":["sr-4117e4afc898dfaa87cdac36cba1a9c4"],"action_type":"investigate","limitations":"Confirm current vendor support, compatibility and deployment evidence. This report has not tested a fix in your system.","current_supported_target":null}],"schema_version":"1.1.0","source_metrics":[{"kind":"CVSS","as_of":"2026-10-28T19:51:40.000Z","value":"8.2 high","meaning":"GitHub source severity; exploitability and local consequence require separate evidence.","source_id":"sr-4117e4afc898dfaa87cdac36cba1a9c4"}],"why_it_matters":"Published affected context helps an owner decide what evidence to gather. This report has not examined your application.","related_sources":[{"id":"sr-4117e4afc898dfaa87cdac36cba1a9c4","url":"https://github.com/advisories/GHSA-4mfg-r38w-w8fg","basis":"vendor_advisory","notes":"GitHub Advisory Database; CC-BY-4.0. Each advisory links its original attribution. Null normalizes fields.","title":"GHSA-4mfg-r38w-w8fg","publisher":"GitHub Advisory Database","observed_at":"2026-10-31T21:56:36.327Z"}],"affected_context":[{"certainty":"source_listed","source_ids":["sr-4117e4afc898dfaa87cdac36cba1a9c4"],"technology":"mcp-sanitizer","known_exclusions":[],"conditions_summary":"## URL sanitizer allows localhost/IPv6 loopback SSRF bypass via explicit port or bracketed IPv6\n\n### Summary\n\n`mcp-sanitizer` v1.3.3 fails to block Server-Side Request Forgery (SSRF) targets when a `localhost` URL includes an explicit port (e.g., `http://localhost:8080/`) or when an IPv6 loopback/link-local address is expressed in bracketed notation (e.g., `http://[::1]:8080/`, `http://[fe80::1]:8080/`). Because the library is explicitly designed to gate MCP tool parameters such as `web_fetch` and `web_scraper` before outbound HTTP requests are made, a bypass here directly enables an attacker-controlled URL to reach internal services, leaking their responses.\n\n### Details\n\nThe vulnerability exists in `src/utils/validation-utils.js` inside the `validateURLLocation()` function that is called by `_secureSanitizeURL()` in `src/sanitizer/mcp-sanitizer.js:698`.\n\n**Bug 1 — Port-guarded localhost check (line 274–276):**\n\n```js\n// src/utils/validation-utils.js:274-276\nif ((hostname === 'localhost' || hostname === '127.0.0.1' || hostname === '::1') && !parsedUrl.port) {\n  throw new Error('URL points to localhost without explicit port');\n}\n```\n\nThe `&& !parsedUrl.port` guard means that any lo","public_affected_ranges":["< 1.4.0"]}],"null_published_at":"2026-10-31T22:13:27.123Z","source_updated_at":"2026-10-28T19:51:40.000Z","source_disclosed_at":"2026-10-28T19:51:39.000Z","is_synthetic_fixture":false,"null_last_reviewed_at":null,"public_change_summary":"First indexed by Null; source disclosure date is shown separately.","null_first_observed_at":"2026-10-31T21:56:36.327Z"}],"next_cursor":null,"snapshot_revision":"42594"}