{"id":"CVE-2026-28490","state":"PUBLISHED","title":"Authlib Vulnerable to JWE RSA1_5 Bleichenbacher Padding Oracle","description":"Authlib is a Python library which builds OAuth and OpenID Connect servers. Prior to version 1.6.9, a cryptographic padding oracle vulnerability was identified in the Authlib Python library concerning the implementation of the JSON Web Encryption (JWE) RSA1_5 key management algorithm. Authlib registers RSA1_5 in its default algorithm registry without requiring explicit opt-in, and actively destroys the constant-time Bleichenbacher mitigation that the underlying cryptography library implements correctly. This issue has been patched in version 1.6.9.","publishedAt":"2026-03-16T17:37:57.425Z","updatedAt":"2026-03-16T18:17:35.003Z","severity":{"score":8.3,"label":"High","version":"4.0","vector":"CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:H/VI:L/VA:N/SC:N/SI:N/SA:N","source":"GitHub_M"},"assigner":"GitHub_M","products":["authlib authlib"],"affected":[{"vendor":"authlib","product":"authlib","versions":[{"version":"< 1.6.9","status":"affected"}]}],"references":["https://github.com/authlib/authlib/security/advisories/GHSA-7432-952r-cw78","https://github.com/authlib/authlib/commit/48b345f29f6c459f11c6a40162b6c0b742ef2e22","https://github.com/authlib/authlib/releases/tag/v1.6.9"],"weaknesses":["CWE-203","CWE-327"],"ingestedAt":"2026-10-29T20:11:31.369Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/28xxx/CVE-2026-28490.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-28490","state":"PUBLISHED","datePublished":"2026-03-16T17:37:57.425Z","dateUpdated":"2026-03-16T18:17:35.003Z","assignerShortName":"GitHub_M","assignerOrgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateReserved":"2026-02-27T20:57:47.707Z"},"containers":{"cna":{"title":"Authlib Vulnerable to JWE RSA1_5 Bleichenbacher Padding Oracle","descriptions":[{"lang":"en","value":"Authlib is a Python library which builds OAuth and OpenID Connect servers. Prior to version 1.6.9, a cryptographic padding oracle vulnerability was identified in the Authlib Python library concerning the implementation of the JSON Web Encryption (JWE) RSA1_5 key management algorithm. Authlib registers RSA1_5 in its default algorithm registry without requiring explicit opt-in, and actively destroys the constant-time Bleichenbacher mitigation that the underlying cryptography library implements correctly. This issue has been patched in version 1.6.9."}],"affected":[{"vendor":"authlib","product":"authlib","versions":[{"version":"< 1.6.9","status":"affected"}]}],"references":[{"url":"https://github.com/authlib/authlib/security/advisories/GHSA-7432-952r-cw78","name":"https://github.com/authlib/authlib/security/advisories/GHSA-7432-952r-cw78","tags":["x_refsource_CONFIRM"]},{"url":"https://github.com/authlib/authlib/commit/48b345f29f6c459f11c6a40162b6c0b742ef2e22","name":"https://github.com/authlib/authlib/commit/48b345f29f6c459f11c6a40162b6c0b742ef2e22","tags":["x_refsource_MISC"]},{"url":"https://github.com/authlib/authlib/releases/tag/v1.6.9","name":"https://github.com/authlib/authlib/releases/tag/v1.6.9","tags":["x_refsource_MISC"]}],"metrics":[{"cvssV4_0":{"attackVector":"NETWORK","attackComplexity":"HIGH","attackRequirements":"PRESENT","privilegesRequired":"NONE","userInteraction":"NONE","vulnConfidentialityImpact":"HIGH","vulnIntegrityImpact":"LOW","vulnAvailabilityImpact":"NONE","subConfidentialityImpact":"NONE","subIntegrityImpact":"NONE","subAvailabilityImpact":"NONE","baseScore":8.3,"baseSeverity":"HIGH","vectorString":"CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:H/VI:L/VA:N/SC:N/SI:N/SA:N","version":"4.0"}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-203","lang":"en","description":"CWE-203: Observable Discrepancy","type":"CWE"}]},{"descriptions":[{"cweId":"CWE-327","lang":"en","description":"CWE-327: Use of a Broken or Risky Cryptographic Algorithm","type":"CWE"}]}],"providerMetadata":{"shortName":"GitHub_M","orgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateUpdated":"2026-03-16T17:37:57.425Z"},"source":{"advisory":"GHSA-7432-952r-cw78","discovery":"UNKNOWN"}},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-03-16T18:17:04.968931Z","id":"CVE-2026-28490","options":[{"Exploitation":"poc"},{"Automatable":"no"},{"Technical Impact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-03-16T18:17:35.003Z"}}]}}}