CVE-2026-39956

MEDIUM EPSS 7.1%
Published Apr 13, 20262mo ago · Modified Jun 17, 20262w ago
6.1 CVSS 3.1
Medium
Find Similar
Published Apr 13, 2026 2mo ago
Last Modified Jun 17, 2026 2w ago

Description

jq is a command-line JSON processor. In commits after 69785bf77f86e2ea1b4a20ca86775916889e91c9, the _strindices builtin in jq's src/builtin.c passes its arguments directly to jv_string_indexes() without verifying they are strings, and jv_string_indexes() in src/jv.c relies solely on assert() checks that are stripped in release builds compiled with -DNDEBUG. This allows an attacker to crash jq trivially with input like _strindices(0), and by crafting a numeric value whose IEEE-754 bit pattern maps to a chosen pointer, achieve a controlled pointer dereference and limited memory read/probe primitive. Any deployment that evaluates untrusted jq filters against a release build is vulnerable. This issue has been patched in commit fdf8ef0f0810e3d365cdd5160de43db46f57ed03.

CVSS Details

Base Score
6.1
Exploitability
1.8
Impact
4.2
Vector string
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:L/I:N/A:H
Attack Vector Local
Attack Complexity Low
Privileges Required None
User Interaction Required
Scope Unchanged
Confidentiality Low
Integrity None
Availability High

Threat Intelligence

EPSS Exploit Probability
7.1% percentile
Exploit & Patch Status
Public Exploit Known
Patch Available

Weaknesses 3

CWE-125 Out-of-bounds Read Memory Safety
CWE-476 NULL Pointer Dereference Memory Safety
CWE-843

Affected Products 1

VendorProductVersionRange
jqlangjq*≥2026-04-02  –  <2026-04-08

References 2

  • github.com https://github.com/jqlang/jq/commit/fdf8ef0f0810e3d365cdd5160de43db46f57ed03
    Patch
  • github.com https://github.com/jqlang/jq/security/advisories/GHSA-6gc3-3g9p-xx28
    ExploitVendor Advisory

Remediation

  • github.com https://github.com/jqlang/jq/commit/fdf8ef0f0810e3d365cdd5160de43db46f57ed03
    Patch