CVE-2026-39956

MEDIUM
MEDIUM Priority: 0.01 BB Relevance: 37/100
Published: 2026-04-13 Modified: 2026-10-26 First seen: 2026-10-29 Status: active

Attack Surface

Low Complexity No Auth

CVSS Vector Breakdown

AV: Local
AC: Low
PR: None
UI: Required
S: Unchanged
C: Low
I: None
A: High

Description

jq is a command-line JSON processor. Prior to version 1.8.2, 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, which is part of version 1.8.2.

Weakness Classification (3)

Affected Software (1)

VendorProductVersion
jqlang jq 2026-04-02 – 2026-04-08

Bug Bounty Relevance

37 / 100
✓ No authentication
✓ Low complexity

CVSS Score

6.1 / 10.0 v3.1
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:L/I:N/A:H

EPSS — Exploitation Probability

0.17%
Raw Score 0.001740
Percentile 6.9%
Date 2026-10-29

EPSS Trend

2026-10-29
0.00174
2026-10-28
0.00174

Intelligence Sources

nvd ref →