CVE-2026-54911
Publication date 22 June 2026
Last updated 26 June 2026
Ubuntu priority
Description
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.
Status
| Package | Ubuntu Release | Status |
|---|---|---|
| ujson | 26.04 LTS resolute |
Needs evaluation
|
| 25.10 questing |
Needs evaluation
|
|
| 24.04 LTS noble |
Needs evaluation
|
|
| 22.04 LTS jammy |
Needs evaluation
|
|
| 20.04 LTS focal |
Needs evaluation
|
|
| 18.04 LTS bionic |
Needs evaluation
|
|
| pandas | 26.04 LTS resolute |
Needs evaluation
|
| 25.10 questing |
Needs evaluation
|
|
| 24.04 LTS noble |
Needs evaluation
|
|
| 22.04 LTS jammy |
Needs evaluation
|
|
| 20.04 LTS focal |
Needs evaluation
|
|
| 18.04 LTS bionic |
Needs evaluation
|
|
| 14.04 LTS trusty |
Needs evaluation
|
|
| collada2gltf | 26.04 LTS resolute | Not in release |
| 25.10 questing | Not in release | |
| 24.04 LTS noble | Not in release | |
| 22.04 LTS jammy |
Needs evaluation
|
|
| 18.04 LTS bionic |
Needs evaluation
|
Notes
ccdm94
the embedded ujson code in pandas, eventhough containing similar content as the upstream ujson code, seems to have diverged from the ujson upstream project (they have fully forked ujson), since pandas upstream is maintaining their own ujson bug fixes and changes without re-syncing with the ujson upstream project. There is no indication the ujson fork, as used in pandas, is vulnerable to the same issues as the upstream ujson code.
Severity score breakdown
CVSS version: CVSS v3.0
Base score
6.5 · Medium
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N