CVE catalog

CVE-2022-31117

ujson: CVE-2022-31117

Severity: Medium · CVSS 5.9CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H
Published: Jul 2, 2022, 12:00:00 AM UTC
Source: [NVD] · [CVE record]
EPSS: 1.88% · Oct 25, 2026

UltraJSON is a fast JSON encoder and decoder written in pure C with bindings for Python 3.7+. In versions prior to 5.4.0 an error occurring while reallocating a buffer for string decoding can cause the buffer to get freed twice. Due to how UltraJSON uses the internal decoder, this double free is impossible to trigger from Python. This issue has been resolved in version 5.4.0 and all users should upgrade to UltraJSON 5.4.0. There are no known workarounds for this issue.

Vulnerable and fixed packages

Distribution-reported package versions and fixes. These do not depend on matching against the OpenFactory package catalog.

Distribution	Package	Release	Version	Status
Debian	ujson	sid	`5.13.0-1`	fixed
Debian	ujson	forky	`5.13.0-1`	fixed
Debian	ujson	trixie	`5.10.0-1`	fixed
Debian	ujson	bookworm	`5.7.0-1`	fixed

Fixed-version evidence

Distribution	Package	Type	Release	Fixed version	Urgency	Origin	Bugs
Debian	ujson	source	sid	`5.4.0-1`	not yet assigned	Not reported	Not reported
Debian	ujson	source	forky	`5.4.0-1`	not yet assigned	Not reported	Not reported
Debian	ujson	source	trixie	`5.4.0-1`	not yet assigned	Not reported	Not reported
Debian	ujson	source	bookworm	`5.4.0-1`	not yet assigned	Not reported	Not reported

OpenFactory catalog packages

[Debian 12 (Bookworm)]

[python3-ujson]Fixed
Source package: [ujson]
Details (2)
- 5.7.0-1 · amd64 · bookworm
  Fixed · Fixed: 5.4.0-1
  dsa · ujson · debian · bookworm
- 5.7.0-1 · arm64 · bookworm
  Fixed · Fixed: 5.4.0-1
  dsa · ujson · debian · bookworm

Observed: Oct 23, 2026, 6:27:04 PM UTC

References

[CERT-Bund public advisories] · [Debian Security Tracker] · [FIRST EPSS] · [Red Hat security advisories and VEX] · [SUSE security advisories and VEX]