SB20260427105 - Multiple vulnerabilities in ultrajson

Description

This security bulletin contains information about 2 vulnerabilities.

1) Integer overflow (CVE-ID: CVE-2026-32875)

The vulnerability allows a remote attacker to cause a denial of service.

The vulnerability exists due to integer overflow or underflow in ujson.dumps() indentation handling when processing user-controlled indent values during JSON serialization of nested input. A remote attacker can supply a specially crafted indent value to cause a denial of service.

The issue can result in a segmentation fault when the indent value and nesting depth exceed INT32_MAX, or an infinite loop when a large negative indent is used.

2) Memory leak (CVE-ID: CVE-2026-32874)

The vulnerability allows a remote attacker to cause a denial of service.

The vulnerability exists due to missing release of memory after effective lifetime in the JSON parser when parsing large integer values in untrusted JSON input. A remote attacker can send a specially crafted JSON payload containing large integers to cause a denial of service.

The issue is triggered for integers outside the range [-2^63, 2^64 - 1], and the leak occurs even if parsing fails because the integer exceeds sys.get_int_max_str_digits().

Remediation

Install update from vendor's website.

References

• https://github.com/ultrajson/ultrajson/security/advisories/GHSA-c8rr-9gxc-jprv
• https://github.com/advisories/GHSA-c8rr-9gxc-jprv
• https://github.com/ultrajson/ultrajson/security/advisories/GHSA-wgvc-ghv9-3pmm
• https://github.com/advisories/GHSA-wgvc-ghv9-3pmm