## Authlib: Default JWT bearer grant accepts assertions for the wrong audience

- 種別: advisory
- 重大度: medium
- 関連技術: python
- CVE: CVE-2026-114618
- 公開日時: 2026-10-27T15:39:08.000Z
- 情報源: GitHub Advisory Database (https://github.com/advisories/GHSA-fch4-3c6x-j4gc)
- パーマリンク: https://vulnpulse.app/items/ghsa-ghsa-fch4-3c6x-j4gc

影響: pip:authlib < 1.9.0 → 1.9.0
Summary Authlib's default RFC 7523 JWT bearer grant leaves get_audiences() empty, so verify_claims() only checks that an aud claim exists instead of requiring it to match the current authorization server's token endpoint. An attacker holding a legitimately issued JWT assertion for any audience can present it to a different authorization server sharing the same signing key and obtain an access token. To be completely transparent, AI tools helped surface it. However, we have independently reprodu…