CVE-2022-31117: Fedoraproject Fedora

Medium severity, CVSS 5.9. EPSS: 1.9% chance of exploitation in the next 30 days.

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.

Affected products

• Fedoraproject Fedora: version 35 only; version 36 only
• Ultrajson Project Ultrajson: before 5.4.0 (fixed in 5.4.0)

Published 2022-07-05. Last modified 2026-06-17.