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Fencer Vulns
medium 6.2

CVE-2026-43894 json

jq: Wild stack write via signed-integer overflow in decNumber D2U() macro

published 2026-05-11 5 mo ago modified 2026-10-26 13 d ago also EUVD-2026-29172

cvss
6.2
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.2%
EPSS 0.2% chance of exploitation in 30 days, percentile 4%
public exploits
0
none known

Summary

jq is a command-line JSON processor. In 1.8.1 and earlier, when decNumberFromString is given a number literal of INT_MAX-1 (2147483646) digits, the D2U() macro overflows during signed-int arithmetic. The wrapped negative value bypasses the heap-allocation size check, causes the function to use a 30-byte stack buffer, and then writes ≈715 million 16-bit units (≈1.4 GiB) at an offset 1.43 GiB below the stack frame. The written content is fully attacker-controlled (the parsed decimal digits, packed 3-per-unit).

Patch / fix

  • jq Debian 12 1.6-2.1+deb12u2
  • jq Debian 13 1.7.1-6+deb13u3
  • jq Debian 14 1.8.1-6

debian advisories DEBIAN-CVE-2026-43894

  • jq hummingbird 1 1.8.2-0.1.hum1

red hat advisories RHSA-2026:29986

  • jq SLES for SAP 15 SP6, SLES for SAP 15 SP5, SLES for SAP 15 SP4 +11 more 1.7.1-150000.3.25.1
  • jq Linux Micro 6.0 1.7.1-1.1
  • jq SLES 16.0, Linux Micro 6.2, SLES for SAP applications 16.0 1.7.1-160000.3.1
  • jq Linux Micro 6.1 1.7.1-slfo.1.1_3.1

suse advisories SUSE-SU-2026:4275-1SUSE-SU-2026:23873-1SUSE-SU-2026:22545-1SUSE-SU-2026:22566-1SUSE-SU-2026:22664-1

  • jq openSUSE Leap 16.0 1.7.1-160000.3.1
  • jq openSUSE Tumbleweed 1.8.1-3.1

opensuse advisories openSUSE-SU-2026:21248-1openSUSE-SU-2026:10850-1

  • jq Alpine 3.24, Alpine 3.23, Alpine 3.22 1.8.2-r0

alpine advisories ALPINE-CVE-2026-43894

Alpine secdb © Alpine Linux, from https://secdb.alpinelinux.org via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2026-43894 updated cvss 6.2

jq: jq: Arbitrary Code Execution or Denial of Service via Signed Integer Overflow

  • Red Hat Ansible Automation Platform 2 automation-controller, ansible-automation-platform-26/hub-rhel9, ansible-automation-platform-26/controller-rhel9
    affected: no fix available, no fix planned “Out of support scope”
  • Red Hat Ceph Storage 4 jq
    affected: no fix planned “Out of support scope”
  • Red Hat Enterprise Linux 8 jq
    affected: no fix available “Fix deferred”
  • Red Hat Enterprise Linux 9 jq
    affected: no fix planned “Out of support scope”
  • Red Hat Enterprise Linux 10 jq Red Hat OpenShift Container Platform 4 openshift/ose-rhel-coreos-8, openshift/ose-rhel-coreos-9
    affected: no fix available “Fix deferred”
  • Red Hat Hardened Images jq 1.8.2-0.1.hum1
    fixed: vendor fix RHSA-2026:29986

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation
Proof of concept is public
Automatable
no
Technical impact
partial
Assessed
5 mo ago

Exploit prediction

0.16% chance of exploitation in the next 30 days, higher than 4% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

  • github.com https://github.com/jqlang/jq/security/advisories/GHSA-5v7p-2r57-2g4g referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
CNA 3.1 6.2 CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
NVD 3.1 5.5 CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

Affected products

  • jqlang jq

Classification

Weakness
  • CWE-190 Integer Overflow or Wraparound

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

CPEs and fixed versions use Anchore's correction of NVD's data: Added CPE configurations because not yet analyzed by NVD.