{"id":"UBUNTU-CVE-2025-61152","details":"python-jose thru 3.3.0 allows JWT tokens with 'alg=none' to be decoded and accepted without any cryptographic signature verification. A malicious actor can craft a forged token with arbitrary claims (e.g., is_admin=true) and bypass authentication checks, leading to privilege escalation or unauthorized access in applications that rely on python-jose for token validation. This issue is exploitable unless developers explicitly reject 'alg=none' tokens, which is not enforced by the library. NOTE: all parties agree that the issue is not relevant because it only occurs in a \"verify_signature\": False situation.","modified":"2025-12-05T11:57:06.414220Z","published":"2025-10-10T14:15:00Z","upstream":["CVE-2025-61152"],"references":[{"type":"REPORT","url":"https://ubuntu.com/security/CVE-2025-61152"},{"type":"REPORT","url":"https://www.cve.org/CVERecord?id=CVE-2025-61152"},{"type":"REPORT","url":"https://github.com/javiermorales36/PoC-for-python-jose-alg-none-JWT-bypass-vulnerability/blob/main/CVE-2025-61152_Security_Advisory.md"},{"type":"REPORT","url":"https://pypi.org/project/python-jose"}],"affected":[{"package":{"name":"python-jose","ecosystem":"Ubuntu:22.04:LTS","purl":"pkg:deb/ubuntu/python-jose@3.3.0+dfsg-1?arch=source&distro=jammy"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["3.3.0+dfsg-1"],"ecosystem_specific":{"binaries":[{"binary_name":"python3-jose","binary_version":"3.3.0+dfsg-1"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2025/UBUNTU-CVE-2025-61152.json"}},{"package":{"name":"python-jose","ecosystem":"Ubuntu:24.04:LTS","purl":"pkg:deb/ubuntu/python-jose@3.3.0+dfsg-4?arch=source&distro=noble"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["3.3.0+dfsg-4"],"ecosystem_specific":{"binaries":[{"binary_version":"3.3.0+dfsg-4","binary_name":"python3-jose"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2025/UBUNTU-CVE-2025-61152.json"}}],"schema_version":"1.7.3","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N"},{"type":"Ubuntu","score":"medium"}]}