UltraJSON is a fast JSON encoder and decoder written in pure C with bindings for Python 3.7+. Prior to 5.12.1, when ujson.dump() writes to a file-like object and the write operation raises an exception, the serialized JSON string object is not decremented, leaking memory. Each failed write operation leaks the full size of the serialized payload. This vulnerability is fixed in 5.12.1.

An update of the python3 package has been released.

The Linux/Unix host has one or more packages installed that are impacted by a vulnerability without a vendor supplied patch available.

  - UltraJSON is a fast JSON encoder and decoder written in pure C with bindings for Python 3.7+. Prior to     5.12.1, when ujson.dump() writes to a file-like object and the write operation raises an exception, the     serialized JSON string object is not decremented, leaking memory. Each failed write operation leaks the     full size of the serialized payload. This vulnerability is fixed in 5.12.1. (CVE-2026-44660)

Note that Nessus relies on the presence of the package as reported by the vendor.

There are packages installed that are affected by a vulnerability referenced in the following CVE:

  - UltraJSON is a fast JSON encoder and decoder written in pure C with bindings for Python 3.7+. Prior to
    5.12.1, when ujson.dump() writes to a file-like object and the write operation raises an exception, the
    serialized JSON string object is not decremented, leaking memory. Each failed write operation leaks the
    full size of the serialized payload. This vulnerability is fixed in 5.12.1. (CVE-2026-44660)

ID	Name	Product	Family	Severity
325970	Photon OS 4.0: Python3 PHSA-2026-4.0-1053	Nessus	PhotonOS Local Security Checks	high
321579	Photon OS 5.0: Python3 PHSA-2026-5.0-0882	Nessus	PhotonOS Local Security Checks	high
318086	Linux Distros Unpatched Vulnerability : CVE-2026-44660	Nessus	Misc.	high
441782	SCA: security update for ujson (GHSA-c38f-wx89-p2xg)	Tenable Cloud Security	SCA Checks	high
441782	SCA: security update for ujson (GHSA-c38f-wx89-p2xg)	Tenable Self-Hosted Container Security	SCA Checks	high

Detections

Analytics

CVE-2026-44660

high

Tenable Plugins

high

high

high

high

high