Buffer overflow in Ultrajson
CVE-2026-32875
UltraJSON is a fast JSON encoder and decoder written in pure C with bindings for Python 3.7+. Versions 5.10 through 5.11.0 are vulnerable to buffer overflow or infinite loop through large indent handling. ujson.dumps() crashes the Python i…
Vulnerability class: Integer Overflow
EPSS: 0.001 (22.1th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.
Affected products
- Ultrajson — versions >= 5.1.0, < 5.12.0
Weakness classification (CWE)
References
- https://github.com/ultrajson/ultrajson/security/advisories/GHSA-c8rr-9gxc-jprv (x_refsource_CONFIRM)
- https://github.com/ultrajson/ultrajson/issues/700 (x_refsource_MISC)
- https://github.com/ultrajson/ultrajson/commit/486bd4553dc471a1de11613bc7347a6b318e37ea (x_refsource_MISC)
Frequently asked questions
- What is CVE-2026-32875?
- CVE-2026-32875 is a high-severity vulnerability in Ultrajson, classified under Integer Overflow or Wraparound. CVSS score: 7.5/10. Published 2026-03-20.
- How severe is CVE-2026-32875?
- High severity. CVSS v3 base score is 7.5 out of 10.