{"id":"DEBIAN-CVE-2026-54911","details":"UltraJSON is a fast JSON encoder and decoder written in pure C with bindings for Python 3.7+. Prior to 5.13.0, ujson.dumps() (or ujson.dump() or ujson.encode()) have a reject_bytes=False option. When set, they may accept malformed or truncated UTF-8 byte sequences, silently rewriting them into different Unicode characters instead of rejecting them. This leads to input validation bypass and data integrity issues. This vulnerability is fixed in 5.13.0.","modified":"2026-09-01T16:06:51.232880706Z","published":"2026-06-22T22:16:50.397Z","upstream":["CVE-2026-54911"],"references":[{"type":"ADVISORY","url":"https://security-tracker.debian.org/tracker/CVE-2026-54911"}],"affected":[{"package":{"name":"ujson","ecosystem":"Debian:12","purl":"pkg:deb/debian/ujson?arch=source&distro=bookworm"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["5.10.0-1","5.11.0-1","5.11.0-2","5.11.0-3","5.13.0-1","5.7.0-1","5.8.0-1","5.9.0-1"],"ecosystem_specific":{"urgency":"not yet assigned"},"database_specific":{"source":"https://storage.googleapis.com/osv-test-debian-osv/debian-cve-osv/DEBIAN-CVE-2026-54911.json"}},{"package":{"name":"ujson","ecosystem":"Debian:13","purl":"pkg:deb/debian/ujson?arch=source&distro=trixie"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["5.10.0-1","5.11.0-1","5.11.0-2","5.11.0-3","5.13.0-1"],"ecosystem_specific":{"urgency":"not yet assigned"},"database_specific":{"source":"https://storage.googleapis.com/osv-test-debian-osv/debian-cve-osv/DEBIAN-CVE-2026-54911.json"}},{"package":{"name":"ujson","ecosystem":"Debian:14","purl":"pkg:deb/debian/ujson?arch=source&distro=forky"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"5.13.0-1"}]}],"versions":["5.10.0-1","5.11.0-1","5.11.0-2","5.11.0-3"],"ecosystem_specific":{"urgency":"not yet assigned"},"database_specific":{"source":"https://storage.googleapis.com/osv-test-debian-osv/debian-cve-osv/DEBIAN-CVE-2026-54911.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:L/I:L/A:N"}]}