{"id":"UBUNTU-CVE-2026-114618","details":"Authlib is a Python library which builds OAuth and OpenID Connect servers. Prior to 1.9.0, the default RFC 7523 JWTBearerGrant.get_audiences() returns an empty list, causing JWTBearerGrant.verify_claims() to require only that an aud claim exists without matching the current authorization server. An attacker holding a legitimate assertion for another service can present it to a server that shares the signing key and uses the default grant, obtaining an access token across a trust boundary. Implementations that override get_audiences() with the server's valid audience identifiers are not affected. This issue is fixed in version 1.9.0.","modified":"2026-10-28T17:50:37Z","published":"2026-10-22T22:18:00Z","upstream":["CVE-2026-114618"],"references":[{"type":"REPORT","url":"https://ubuntu.com/security/CVE-2026-114618"},{"type":"REPORT","url":"https://www.cve.org/CVERecord?id=CVE-2026-114618"},{"type":"REPORT","url":"https://github.com/authlib/authlib/commit/e3bd41cb29dcfee434453b135ffb487884baeedf"},{"type":"REPORT","url":"https://github.com/authlib/authlib/pull/945"},{"type":"REPORT","url":"https://github.com/authlib/authlib/releases/tag/v1.9.0"},{"type":"REPORT","url":"https://github.com/authlib/authlib/security/advisories/GHSA-fch4-3c6x-j4gc"}],"affected":[{"package":{"name":"python-authlib","ecosystem":"Ubuntu:Pro:22.04:LTS","purl":"pkg:deb/ubuntu/python-authlib?arch=source&distro=esm-apps%2Fjammy"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["0.15.4-1","0.15.5-1","0.15.5-1ubuntu0.1~esm1","0.15.5-1ubuntu0.1~esm2"],"ecosystem_specific":{"binaries":[{"binary_name":"python3-authlib","binary_version":"0.15.5-1ubuntu0.1~esm2"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-114618.json"}},{"package":{"name":"python-authlib","ecosystem":"Ubuntu:Pro:24.04:LTS","purl":"pkg:deb/ubuntu/python-authlib?arch=source&distro=esm-apps%2Fnoble"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["1.2.1-1","1.3.0-1","1.3.0-1ubuntu0.1~esm1","1.3.0-1ubuntu0.1~esm2"],"ecosystem_specific":{"binaries":[{"binary_name":"python3-authlib","binary_version":"1.3.0-1ubuntu0.1~esm2"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-114618.json"}},{"package":{"name":"python-authlib","ecosystem":"Ubuntu:26.10","purl":"pkg:deb/ubuntu/python-authlib?arch=source&distro=stonking"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["1.6.7-1","1.7.2-1","1.7.2-2"],"ecosystem_specific":{"binaries":[{"binary_name":"python3-authlib","binary_version":"1.7.2-2"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-114618.json"}},{"package":{"name":"python-authlib","ecosystem":"Ubuntu:Pro:26.04:LTS","purl":"pkg:deb/ubuntu/python-authlib?arch=source&distro=esm-apps%2Fresolute"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["1.6.0-1","1.6.5-1","1.6.6-1","1.6.7-1","1.6.7-1ubuntu0.1~esm1"],"ecosystem_specific":{"binaries":[{"binary_version":"1.6.7-1ubuntu0.1~esm1","binary_name":"python3-authlib"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-114618.json"}}],"schema_version":"1.9.2","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:N"},{"type":"Ubuntu","score":"medium"}]}