PYSEC-2026-1056
See a problem?- Import Source
- https://github.com/pypa/advisory-database/blob/main/vulns/ujson/PYSEC-2026-1056.yaml
- JSON Data
- https://api.osv.dev/v1/vulns/PYSEC-2026-1056
- Aliases
- Published
- 2026-07-06T08:03:30.989917Z
- Modified
- 2026-07-07T11:46:02.150833922Z
- Severity
-
- 5.9 (Medium) CVSS_V3 - CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H CVSS Calculator
- Summary
- Potential double free of buffer during string decoding
- Details
-
Impact
What kind of vulnerability is it? Who is impacted?
When an error occurs while reallocating the buffer for string decoding, the buffer gets freed twice.
Due to how UltraJSON uses the internal decoder, this double free is impossible to trigger from Python.
Patches
Has the problem been patched? What versions should users upgrade to?
Users should upgrade to UltraJSON 5.4.0.
Workarounds
Is there a way for users to fix or remediate the vulnerability without upgrading?
There is no workaround.
For more information
If you have any questions or comments about this advisory: * Open an issue in UltraJSON
- References
-
- https://github.com/ultrajson/ultrajson/security/advisories/GHSA-fm67-cv37-96ff
- https://nvd.nist.gov/vuln/detail/CVE-2022-31117
- https://github.com/ultrajson/ultrajson/commit/9c20de0f77b391093967e25d01fb48671104b15b
- https://github.com/ultrajson/ultrajson
- https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/NAU5N4A7EUK2AMUCOLYDD5ARXAJYZBD2
- https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/OPPU5FZP3LCTXYORFH7NHUMYA5X66IA7
- https://pypi.org/project/ujson
- https://github.com/advisories/GHSA-fm67-cv37-96ff
Affected packages
PyPI / ujson
Package
- Name
- ujson
- View open source insights on deps.dev
- Purl
- pkg:pypi/ujson
Affected ranges
- Type
- ECOSYSTEM
- Events
-
Introduced0Unknown introduced version / All previous versions are affectedFixed5.4.0