{"id":"CVE-2026-114616","summary":"Authlib accepts an empty HMAC key, allowing JWS/JWT signature forgery (HS256/HS384/HS512)","details":"Authlib is a Python library which builds OAuth and OpenID Connect servers. Prior to 1.9.1, Authlib's OctKey.import_key() and HMAC signing and verification path accept zero-length key material. If an application's secret lookup can return an empty string or empty bytes, a remote attacker can compute the deterministic HS256, HS384, or HS512 signature for arbitrary token claims and have Authlib treat the token as authentic. This issue is fixed in version 1.9.1.","aliases":["GHSA-8m4g-j4wp-wgcg","PYSEC-2026-4356"],"modified":"2026-11-03T17:27:21.175260601Z","published":"2026-10-22T21:14:03.060Z","related":["openSUSE-SU-2026:12390-1"],"database_specific":{"cna_assigner":"GitHub_M","cwe_ids":["CWE-1391","CWE-287","CWE-326"],"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/114xxx/CVE-2026-114616.json"},"references":[{"type":"WEB","url":"https://github.com/authlib/authlib/releases/tag/v1.9.1"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/114xxx/CVE-2026-114616.json"},{"type":"ADVISORY","url":"https://github.com/authlib/authlib/security/advisories/GHSA-8m4g-j4wp-wgcg"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-114616"},{"type":"FIX","url":"https://github.com/authlib/authlib/commit/4ff30db442c70e29486e1982cb0ad37c037f5f4b"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://github.com/authlib/authlib","events":[{"introduced":"0"},{"fixed":"46b94870d915ee77430da8fa2a358378d90b3a45"},{"fixed":"4ff30db442c70e29486e1982cb0ad37c037f5f4b"}],"database_specific":{"extracted_events":[{"range":[{"introduced":"0"},{"fixed":"1.9.1"}],"source":"CPE_RANGE","cpe":"cpe:2.3:a:authlib:authlib:*:*:*:*:*:*:*:*"},{"range":[{"fixed":"4ff30db442c70e29486e1982cb0ad37c037f5f4b"}],"source":"REFERENCES_COMMIT"},{"source":"REFERENCES_TAG","original_tag":"v1.9.1","range":[{"fixed":"46b94870d915ee77430da8fa2a358378d90b3a45"}]}]}}],"versions":["v1.9.0","v1.8.0","v1.7.2","v1.7.1","1.7.1","v1.7.0","v1.6.6","v1.6.5","v1.6.4","v1.6.3","v1.6.2","v1.6.1","v1.6.0","v1.5.2","v1.5.1","v1.5.0","v1.4.1","v1.4.0","v1.3.2","v1.3.0","v1.2.1","v1.2.0","v1.1.0","v1.0.1","v1.0.0","v0.15","v0.14.3","v0.14.2","v0.14.1","v0.14","v0.13","v0.12","v0.11","v0.10","v0.9","v0.8","v0.7","v0.6","v0.5.1","v0.5","v0.4.1","v0.4","v0.3","v0.2.1","v0.2","v0.1"],"database_specific":{"source":"https://storage.googleapis.com/osv-test-cve-osv-conversion/osv-output/CVE-2026-114616.json"}}],"schema_version":"1.9.2","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N"}]}