CVE-2026-39956

Severity CVSS v4.0:

Pending analysis

Type:

CWE-125 Out-of-bounds Read

Publication date:

13/04/2026

Last modified:

21/04/2026

Description

jq is a command-line JSON processor. In commits after 69785bf77f86e2ea1b4a20ca86775916889e91c9, the _strindices builtin in jq&#39;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.

Impact

Vector 3.x

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

Base Score: 6.10 MEDIUM
Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:L/I:N/A:H

Attack Vector (AV): Local
Attack Complexity (AC): Low
Privileges Required (PR): None
User Interaction (UI): Required
Scope (S): Unchanged
Confidentiality (C): Low
Integrity (I): None
Availability (A): High