{"id":"DEBIAN-CVE-2026-48525","details":"PyJWT is a JSON Web Token implementation in Python. From 2.8.0 to 2.12.1, when verifying detached JWS tokens using the unencoded-payload option (\"b64\": false, RFC 7797), PyJWT performs Base64URL decoding of the compact-serialization payload segment before enforcing the detached-payload rules. For b64=false, PyJWT later discards that decoded payload and replaces it with the caller-provided detached_payload. In practice, this turns the middle segment into an attacker-controlled “work amplifier”: a remote client can supply an arbitrarily large Base64URL payload segment that forces CPU work + memory allocations even if the signature is invalid. This creates an unauthenticated DoS vector against any endpoint that verifies detached JWS using PyJWT. This vulnerability is fixed in 2.13.0.","modified":"2026-08-27T23:05:31.407154380Z","published":"2026-05-28T16:16:29.533Z","upstream":["CVE-2026-48525"],"references":[{"type":"ADVISORY","url":"https://security-tracker.debian.org/tracker/CVE-2026-48525"}],"affected":[{"package":{"name":"pyjwt","ecosystem":"Debian:12","purl":"pkg:deb/debian/pyjwt?arch=source&distro=bookworm"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["2.10.1-1","2.10.1-2","2.10.1-3","2.10.1-4","2.11.0-2","2.12.1-1","2.13.0-1","2.6.0-1","2.6.0-1+deb12u1","2.7.0-1"],"ecosystem_specific":{"urgency":"not yet assigned"},"database_specific":{"source":"https://storage.googleapis.com/osv-test-debian-osv/debian-cve-osv/DEBIAN-CVE-2026-48525.json"}},{"package":{"name":"pyjwt","ecosystem":"Debian:13","purl":"pkg:deb/debian/pyjwt?arch=source&distro=trixie"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["2.10.1-2","2.10.1-2+deb13u1","2.10.1-3","2.10.1-4","2.11.0-2","2.12.1-1","2.13.0-1"],"ecosystem_specific":{"urgency":"not yet assigned"},"database_specific":{"source":"https://storage.googleapis.com/osv-test-debian-osv/debian-cve-osv/DEBIAN-CVE-2026-48525.json"}},{"package":{"name":"pyjwt","ecosystem":"Debian:14","purl":"pkg:deb/debian/pyjwt?arch=source&distro=forky"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"2.13.0-1"}]}],"versions":["2.10.1-2","2.10.1-3","2.10.1-4","2.11.0-2","2.12.1-1"],"ecosystem_specific":{"urgency":"not yet assigned"},"database_specific":{"source":"https://storage.googleapis.com/osv-test-debian-osv/debian-cve-osv/DEBIAN-CVE-2026-48525.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L"}]}