CVE-2026-39979

Public on 2026-04-13
Modified on 2026-04-15
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.
Severity
Medium severity
Medium
See what this means
CVSS v3 Base Score
6.1
See breakdown

Affected Packages

Platform Package Release Date Advisory Status
Amazon Linux 2 - Core jq Pending Fix
Amazon Linux 2023 jq Pending Fix

CVSS Scores

Score Type Score Vector
Amazon Linux CVSSv3 6.1 CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:L/I:N/A:H