{"id":"DEBIAN-CVE-2026-49852","details":"joserfc is a Python library that provides an implementation of several JSON Object Signing and Encryption (JOSE) standards. Prior to 1.6.8, joserfc.jwt.decode accepts attacker-forged HMAC-signed tokens when the caller-supplied verification key is the empty string or None, because HMACAlgorithm.sign and HMACAlgorithm.verify in src/joserfc/_rfc7518/jws_algs.py pass the output of OctKey.get_op_key(...) to hmac.new(...) and OctKey.import_key in src/joserfc/_rfc7518/oct_key.py only emits a SecurityWarning for keys shorter than 14 bytes without rejecting zero-length input. This issue is fixed in version 1.6.8.","modified":"2026-08-27T23:05:31.844159214Z","published":"2026-07-17T20:17:23.270Z","upstream":["CVE-2026-49852"],"references":[{"type":"ADVISORY","url":"https://security-tracker.debian.org/tracker/CVE-2026-49852"}],"affected":[{"package":{"name":"joserfc","ecosystem":"Debian:13","purl":"pkg:deb/debian/joserfc?arch=source&distro=trixie"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["1.1.0-1","1.2.0-1","1.2.2-1","1.3.1-1","1.3.2-1","1.3.4-1","1.4.0-1","1.4.1-1","1.4.3-1","1.5.0-1","1.6.0-1","1.6.1-1","1.6.2-1","1.6.3-1","1.6.4-1","1.6.5-1","1.6.8-1","1.7.0-1","1.7.1-1","1.7.2-1","1.7.3-1","1.7.4-1"],"ecosystem_specific":{"urgency":"not yet assigned"},"database_specific":{"source":"https://storage.googleapis.com/osv-test-debian-osv/debian-cve-osv/DEBIAN-CVE-2026-49852.json"}},{"package":{"name":"joserfc","ecosystem":"Debian:14","purl":"pkg:deb/debian/joserfc?arch=source&distro=forky"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1.6.8-1"}]}],"versions":["1.1.0-1","1.2.0-1","1.2.2-1","1.3.1-1","1.3.2-1","1.3.4-1","1.4.0-1","1.4.1-1","1.4.3-1","1.5.0-1","1.6.0-1","1.6.1-1","1.6.2-1","1.6.3-1","1.6.4-1","1.6.5-1"],"ecosystem_specific":{"urgency":"not yet assigned"},"database_specific":{"source":"https://storage.googleapis.com/osv-test-debian-osv/debian-cve-osv/DEBIAN-CVE-2026-49852.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V4","score":"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:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X"}]}