{"items":[{"id":"NVI-00011703","kind":"vulnerability","title":"agent-router: MCP session resume does not verify the embedded anti-hijacking subject; default Helm seed makes session IDs forgeable","revision":1,"unknowns":["Customer inventory, deployment, reachability and exploitation have not been inspected."],"lifecycle":"active","identifiers":["GHSA-953h-535j-jg2v"],"plain_summary":"GitHub lists this reviewed advisory for github.com/envoyproxy/ai-gateway. 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-06d9de090f8c3a7389e9f5378ad8f48f"],"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":[],"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-06d9de090f8c3a7389e9f5378ad8f48f","url":"https://github.com/advisories/GHSA-953h-535j-jg2v","basis":"vendor_advisory","notes":"GitHub Advisory Database; CC-BY-4.0. Each advisory links its original attribution. Null normalizes fields.","title":"GHSA-953h-535j-jg2v","publisher":"GitHub Advisory Database","observed_at":"2026-10-31T23:14:14.588Z"}],"affected_context":[{"certainty":"source_listed","source_ids":["sr-06d9de090f8c3a7389e9f5378ad8f48f"],"technology":"github.com/envoyproxy/ai-gateway","known_exclusions":[],"conditions_summary":"## Summary\n\nThe MCP proxy's client-facing session ID embeds the authenticated caller's\nsubject (JWT `sub` claim) specifically as an anti-hijacking discriminator —\nmatching the Model Context Protocol specification's documented session-hijacking\nguidance (https://modelcontextprotocol.io/specification/2025-06-18/basic/security_best_practices#session-hijacking).\nHowever, the session-resume path never checks that discriminator against the\ncurrent caller's identity, so any client that obtains a session ID (its own or\nanother user's) can resume that session and act with it — including on\nroutes with per-user backend sessions. This is aggravated by the official\nHelm chart shipping a literal, publicly known default seed\n(`\"default-insecure-seed\"`) for the key that encrypts these session IDs.\n\n## Impact\n\nAn attacker who obtains (or, under the default seed, forges) another user's\n`Mcp-Session-Id` value can resume that user's MCP session against the backend\nMCP server(s) bound to the route — reading conversation/tool-call state and\ninvoking further JSON-RPC methods (e.g. `tools/call`, `resources/read`) in the\ncontext of that other user's already-initialized backend session. On a\nmulti-tenant A","public_affected_ranges":[">= 0.4.0-rc1, < 1.2.0-rc1"]}],"null_published_at":"2026-11-01T01:03:56.586Z","source_updated_at":"2026-10-19T16:53:27.000Z","source_disclosed_at":"2026-10-19T16:53:26.000Z","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":"2026-10-31T23:14:14.588Z"}],"next_cursor":null,"snapshot_revision":"42594"}