CVE-2026-39979

CVE Details

Release Date:	2026-04-13
Impact:	Important	What is this?

Description

jq is a command-line JSON processor. In commits before 2f09060afab23fe9390cce7cb860b10416e1bf5f, the jv_parse_sized() API in libjq accepts a counted buffer with an explicit length parameter, but its error-handling path formats the input buffer using %s in jv_string_fmt(), which reads until a NUL terminator is found rather than respecting the caller-supplied length. This means that when malformed JSON is passed in a non-NUL-terminated buffer, the error construction logic performs an out-of-bounds read past the end of the buffer. The vulnerability is reachable by any libjq consumer calling jv_parse_sized() with untrusted input, and depending on memory layout, can result in memory disclosure or process termination. The issue has been patched in commit 2f09060afab23fe9390cce7cb860b10416e1bf5f.

See more information about CVE-2026-39979 from MITRE CVE dictionary and NIST NVD

NOTE: The following CVSS metrics and score provided are preliminary and subject to review.

CVSS v3 metrics

Base Score:	8.2
Vector String:	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:H
Version:	3.1
Attack Vector:	Network
Attack Complexity:	Low
Privileges Required:	None
User Interaction:	None
Scope:	Unchanged
Confidentiality Impact:	Low
Integrity Impact:	None
Availability Impact:	High

Errata information

Platform	Errata	Release Date
Oracle Linux version 10 (jq)	ELSA-2026-16692	2026-05-13
Oracle Linux version 8 (jq)	ELSA-2026-16252	2026-05-13
Oracle Linux version 9 (jq)	ELSA-2026-16693	2026-05-13