## agent-router: MCP session resume does not verify the embedded anti-hijacking subject; default Helm seed makes session IDs forgeable

- 種別: advisory
- 重大度: medium
- 関連技術: go, github
- 公開日時: 2026-10-19T16:53:26.000Z
- 情報源: GitHub Advisory Database (https://github.com/advisories/GHSA-953h-535j-jg2v)
- パーマリンク: https://vulnpulse.app/items/ghsa-ghsa-953h-535j-jg2v

影響: go:github.com/envoyproxy/ai-gateway >= 0.4.0-rc1, < 1.2.0-rc1 → 1.2.0-rc1
Summary The MCP proxy's client-facing session ID embeds the authenticated caller's subject (JWT sub claim) specifically as an anti-hijacking discriminator — matching the Model Context Protocol specification's documented session-hijacking guidance (https://modelcontextprotocol.io/specification/2025-06-18/basic/security_best_practices#session-hijacking). However, the session-resume path never checks that discriminator against the current caller's identity, so any client that obtains a session ID…