Vulnerability in Ultrajson
CVE-2026-32874
UltraJSON is a fast JSON encoder and decoder written in pure C with bindings for Python 3.7+. Versions 5.4.0 through 5.11.0 contain an accumulating memory leak in JSON parsing large (outside of the range [-2^63, 2^64 - 1]) integers. The le…
EPSS: 0.005 (38.3th 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 >= 5.4.0, < 5.12.0
- Ultrajson_project Ultrajson
Weakness classification (CWE)
References
- security-advisories@github.com (x_refsource_CONFIRM, Vendor Advisory)
- security-advisories@github.com (Patch, x_refsource_MISC)
- security-advisories@github.com (Product, x_refsource_MISC, Release Notes)
- 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
- 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
- 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
Frequently asked questions
- What is CVE-2026-32874?
- CVE-2026-32874 is a high-severity vulnerability in Ultrajson, classified under Missing Release of Memory after Effective Lifetime. CVSS score: 7.5/10. Published 2026-03-20.
- How severe is CVE-2026-32874?
- High severity. CVSS v3 base score is 7.5 out of 10.