CVE-2026-44660
Description
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.
Predictions
Heuristic predictions, AS-IS, for prioritization only.
Mitigations
No mitigations published for this CVE yet.
The vendor-content worker queues fetches as references arrive (check back in a few minutes). Or — if you've already worked around this in production — publish your fix to the community-verified tier.
✚ Propose a mitigation on Community → Mitigations published via the community go through AI scoring + 2 human reviewers + 7-day silent objection window before landing here withsource_tier=community-verified.
References
- https://github.com/ultrajson/ultrajson/security/advisories/GHSA-c38f-wx89-p2xg
- https://github.com/ultrajson/ultrajson/commit/82af1d0ac01d09aa40c887b460d44b9d9f4bccd9
- https://github.com/ultrajson/ultrajson
- https://github.com/ultrajson/ultrajson/releases/tag/5.12.1
- https://github.com/advisories/GHSA-c38f-wx89-p2xg
CWEs
CWE-401
Community-verified mitigations for this CVE will appear above when contributors publish them.
Verify integrity in audit chain (admin only). AS-IS.