{"id":"CVE-2026-59163","published":"2026-09-18T18:17:07.807","lastModified":"2026-09-24T21:25:27.050","description":"Mnemosyne is a memory layer for artificial intelligence agents. Prior to v3.10.1, the auth check in mnemosyne/core/sync_server.py parsed the JWT's header and payload using base64 decoding, then passed the token to a jwt library call with options that effectively disabled signature verification. The server accepted any well-formed token regardless of the signature, including tokens with alg: none and tokens signed with the wrong key. The fix in v3.10.1 replaces the broken decode with a from-scratch HS256 verifier using only the Python standard library. For users who cannot upgrade immediately, restrict network access to the sync server endpoint to trusted clients only. Firewall, reverse proxy with mTLS, or localhost bind with SSH tunnel are all viable. The vulnerability is not exploitable against an unreachable endpoint.","cvssScore":9.1,"cvssSeverity":"CRITICAL","cvssVector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N","cwes":["CWE-347"],"vendors":[],"products":[],"references":[{"url":"https://github.com/mnemosyne-oss/mnemosyne/commit/a0b6b8711a1a485304971710dc3571e29ff9dbeb","tags":[]},{"url":"https://github.com/mnemosyne-oss/mnemosyne/pull/373","tags":[]},{"url":"https://github.com/mnemosyne-oss/mnemosyne/releases/tag/v3.10.1","tags":[]},{"url":"https://github.com/mnemosyne-oss/mnemosyne/security/advisories/GHSA-xcw4-53cc-hv32","tags":[]},{"url":"https://github.com/mnemosyne-oss/mnemosyne/security/advisories/GHSA-xcw4-53cc-hv32","tags":[]}],"exploitRefs":[{"url":"https://github.com/mnemosyne-oss/mnemosyne/commit/a0b6b8711a1a485304971710dc3571e29ff9dbeb","tags":[]},{"url":"https://github.com/mnemosyne-oss/mnemosyne/pull/373","tags":[]},{"url":"https://github.com/mnemosyne-oss/mnemosyne/releases/tag/v3.10.1","tags":[]},{"url":"https://github.com/mnemosyne-oss/mnemosyne/security/advisories/GHSA-xcw4-53cc-hv32","tags":[]},{"url":"https://github.com/mnemosyne-oss/mnemosyne/security/advisories/GHSA-xcw4-53cc-hv32","tags":[]}],"hasPoc":true,"ai":{"summary":"The flaw in Mnemosyne allows any well-formed token to be accepted by the sync server, bypassing signature verification, which could lead to unauthorized access to the system.","exploitability":"Exploitation is relatively easy if an attacker can send a crafted token to the sync server. Precondition is network access to the sync server endpoint.","blast_radius":"If exploited, the vulnerability could allow an attacker to gain full control over the system, potentially leading to data theft or system compromise.","remediation":"Restrict network access to the sync server endpoint to trusted clients only. Firewall, reverse proxy with mTLS, or localhost bind with SSH tunnel are all viable options. Upgrade to v3.10.1 or later.","detection":"No reliable host or network indicator is derivable from the published description.","tags":["auth-bypass","jwt","api","network"],"model":"qwen2.5:7b-instruct","analyzedAt":"2026-09-28T09:06:43.202Z"}}