DEBIAN-CVE-2026-54911
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.
DEBIAN-CVE-2026-54911
Primary source · Revision 1
Imported from structured advisory data. Source references identify upstream records or fields; verify affected versions and your deployed configuration.
Security context
Source reference: osv:DEBIAN-CVE-2026-54911
ujson
Source reference: /affected/0/package/name
- Affected versions
- 5.10.0-1
Source reference:
/affected/0/versions5.11.0-1Source reference:
/affected/0/versions5.11.0-2Source reference:
/affected/0/versions5.11.0-3Source reference:
/affected/0/versions5.13.0-1Source reference:
/affected/0/versions5.7.0-1Source reference:
/affected/0/versions5.8.0-1Source reference:
/affected/0/versions5.9.0-1Source reference:
/affected/0/versions - Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
ujson
Source reference: /affected/1/package/name
- Affected versions
- 5.10.0-1
Source reference:
/affected/1/versions5.11.0-1Source reference:
/affected/1/versions5.11.0-2Source reference:
/affected/1/versions5.11.0-3Source reference:
/affected/1/versions5.13.0-1Source reference:
/affected/1/versions - Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
ujson
Source reference: /affected/2/package/name
- Affected versions
- 5.10.0-1
Source reference:
/affected/2/versions5.11.0-1Source reference:
/affected/2/versions5.11.0-2Source reference:
/affected/2/versions5.11.0-3Source reference:
/affected/2/versions - Fixed versions
- 5.13.0-1
Source reference:
/affected/2/ranges - Prerequisites
- Not stated in this record
Structured affected-version data
Original package identities and version rules from this source.
[
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
}
]
}
],
"package": {
"name": "ujson",
"purl": "pkg:deb/debian/ujson?arch=source&distro=bookworm",
"ecosystem": "Debian:12"
},
"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"
],
"database_specific": {
"source": "https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-54911.json"
},
"ecosystem_specific": {
"urgency": "not yet assigned"
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
}
]
}
],
"package": {
"name": "ujson",
"purl": "pkg:deb/debian/ujson?arch=source&distro=trixie",
"ecosystem": "Debian:13"
},
"versions": [
"5.10.0-1",
"5.11.0-1",
"5.11.0-2",
"5.11.0-3",
"5.13.0-1"
],
"database_specific": {
"source": "https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-54911.json"
},
"ecosystem_specific": {
"urgency": "not yet assigned"
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
},
{
"fixed": "5.13.0-1"
}
]
}
],
"package": {
"name": "ujson",
"purl": "pkg:deb/debian/ujson?arch=source&distro=forky",
"ecosystem": "Debian:14"
},
"versions": [
"5.10.0-1",
"5.11.0-1",
"5.11.0-2",
"5.11.0-3"
],
"database_specific": {
"source": "https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-54911.json"
},
"ecosystem_specific": {
"urgency": "not yet assigned"
}
}
]Publisher severity
No explicit severity was provided.
- Event
- #57846 · Revision 1
- Added to Heist Feed
- Publisher date