Vulnerability in Ultrajson
CVE-2026-44660
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…
EPSS: 0.001 (16.7th 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 < 5.12.1
- Ultrajson_project Ultrajson
Weakness classification (CWE)
References
- security-advisories@github.com (x_refsource_CONFIRM, Exploit, Patch, Mitigation, Vendor Advisory)
- security-advisories@github.com (Patch, x_refsource_MISC)
- security-advisories@github.com (Product, x_refsource_MISC, Release Notes)
Frequently asked questions
- What is CVE-2026-44660?
- CVE-2026-44660 is a high-severity vulnerability in Ultrajson, classified under Missing Release of Memory after Effective Lifetime. CVSS score: 7.5/10. Published 2026-05-27.
- How severe is CVE-2026-44660?
- High severity. CVSS v3 base score is 7.5 out of 10.