{"id":"UBUNTU-CVE-2026-48990","details":"joserfc is a Python library that provides an implementation of several JSON Object Signing and Encryption (JOSE) standards. In versions 1.3.4 through 1.6.5, joserfc accepts oversized RFC7797 b64=false JWS payloads without applying JWSRegistry.max_payload_length, which can lead to resource exhaustion. The normal JWS compact and flattened JSON paths reject payloads above the configured payload-size limit with ExceededSizeError. The RFC7797 unencoded payload paths do not make the same check. A valid b64=false compact or flattened JSON JWS can therefore deserialize successfully with a payload larger than JWSRegistry.max_payload_length. Applications that accept lower-trust JWS values and rely on joserfc to reject oversized token content during verification have a moderate availability risk. This issue has been fixed in version 1.6.7.","modified":"2026-06-24T11:01:42.774836661Z","published":"2026-06-17T22:16:00Z","upstream":["CVE-2026-48990"],"references":[{"type":"REPORT","url":"https://ubuntu.com/security/CVE-2026-48990"},{"type":"REPORT","url":"https://www.cve.org/CVERecord?id=CVE-2026-48990"},{"type":"REPORT","url":"https://github.com/authlib/joserfc/security/advisories/GHSA-wphv-vfrh-23q5"}],"affected":[{"package":{"name":"joserfc","ecosystem":"Ubuntu:25.10","purl":"pkg:deb/ubuntu/joserfc?arch=source&distro=questing"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["1.0.4-1","1.1.0-1","1.2.0-1","1.2.2-1"],"ecosystem_specific":{"binaries":[{"binary_version":"1.2.2-1","binary_name":"python3-joserfc"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-48990.json"}},{"package":{"name":"joserfc","ecosystem":"Ubuntu:26.04:LTS","purl":"pkg:deb/ubuntu/joserfc?arch=source&distro=resolute"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["1.2.2-1","1.4.0-1","1.4.1-1","1.4.3-1","1.5.0-1","1.6.2-1"],"ecosystem_specific":{"binaries":[{"binary_version":"1.6.2-1","binary_name":"python3-joserfc"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-48990.json"}}],"schema_version":"1.7.5","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L"},{"type":"Ubuntu","score":"medium"}]}