{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-28802","assignerOrgId":"a0819718-46f1-4df5-94e2-005712e83aaa","state":"PUBLISHED","assignerShortName":"GitHub_M","dateReserved":"2026-03-03T14:25:19.246Z","datePublished":"2026-03-06T06:44:26.402Z","dateUpdated":"2026-03-06T16:05:35.082Z"},"containers":{"cna":{"title":"Authlib: Setting `alg: none` and a blank signature appears to bypass signature verification","problemTypes":[{"descriptions":[{"cweId":"CWE-347","lang":"en","description":"CWE-347: Improper Verification of Cryptographic Signature","type":"CWE"}]}],"metrics":[{"cvssV4_0":{"attackVector":"NETWORK","attackComplexity":"LOW","attackRequirements":"NONE","privilegesRequired":"NONE","userInteraction":"NONE","vulnConfidentialityImpact":"NONE","vulnIntegrityImpact":"HIGH","vulnAvailabilityImpact":"NONE","subConfidentialityImpact":"NONE","subIntegrityImpact":"NONE","subAvailabilityImpact":"NONE","baseScore":7.7,"baseSeverity":"HIGH","vectorString":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N/E:P","version":"4.0"}}],"references":[{"name":"https://github.com/authlib/authlib/security/advisories/GHSA-7wc2-qxgw-g8gg","tags":["x_refsource_CONFIRM"],"url":"https://github.com/authlib/authlib/security/advisories/GHSA-7wc2-qxgw-g8gg"},{"name":"https://github.com/authlib/authlib/commit/a61c2acb807496e67f32051b5f1b1d5ccf8f0a75","tags":["x_refsource_MISC"],"url":"https://github.com/authlib/authlib/commit/a61c2acb807496e67f32051b5f1b1d5ccf8f0a75"},{"name":"https://github.com/authlib/authlib/commit/b87c32ed07b8ae7f805873e1c9cafd1016761df7","tags":["x_refsource_MISC"],"url":"https://github.com/authlib/authlib/commit/b87c32ed07b8ae7f805873e1c9cafd1016761df7"}],"affected":[{"vendor":"authlib","product":"authlib","versions":[{"version":">= 1.6.5, < 1.6.7","status":"affected"}]}],"providerMetadata":{"orgId":"a0819718-46f1-4df5-94e2-005712e83aaa","shortName":"GitHub_M","dateUpdated":"2026-03-06T06:44:26.402Z"},"descriptions":[{"lang":"en","value":"Authlib is a Python library which builds OAuth and OpenID Connect servers. From version 1.6.5 to before version 1.6.7, previous tests involving passing a malicious JWT containing alg: none and an empty signature was passing the signature verification step without any changes to the application code when a failure was expected.. This issue has been patched in version 1.6.7."}],"source":{"advisory":"GHSA-7wc2-qxgw-g8gg","discovery":"UNKNOWN"}},"adp":[{"metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-03-06T16:00:04.267898Z","id":"CVE-2026-28802","options":[{"Exploitation":"none"},{"Automatable":"yes"},{"Technical Impact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"title":"CISA ADP Vulnrichment","providerMetadata":{"orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","shortName":"CISA-ADP","dateUpdated":"2026-03-06T16:05:35.082Z"}}]}}