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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.

PUBLISHED Reserved 2026-04-07 | Published 2026-04-13 | Updated 2026-04-14 | Assigner GitHub_M




MEDIUM: 6.1CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:L/I:N/A:H

Problem types

CWE-125: Out-of-bounds Read

CWE-476: NULL Pointer Dereference

CWE-843: Access of Resource Using Incompatible Type ('Type Confusion')

Product status

>= 69785bf77f86e2ea1b4a20ca86775916889e91c9, < fdf8ef0f0810e3d365cdd5160de43db46f57ed03
affected

References

github.com/jqlang/jq/security/advisories/GHSA-6gc3-3g9p-xx28 exploit

github.com/jqlang/jq/security/advisories/GHSA-6gc3-3g9p-xx28

github.com/...ommit/fdf8ef0f0810e3d365cdd5160de43db46f57ed03

cve.org (CVE-2026-39956)

nvd.nist.gov (CVE-2026-39956)

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