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Fencer Vulns
medium 5.5

CVE-2026-41256 json

jq: Embedded NUL truncates top-level jq programs loaded with -f

published 2026-05-11 5 mo ago modified 2026-10-26 13 d ago also EUVD-2026-29162

cvss
5.5
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, Top-level jq programs loaded from a file with -f are truncated at the first embedded NUL byte on current upstream HEAD. A crafted filter file such as . followed by \x00 and arbitrary suffix compiles and executes as only the prefix before the NUL. This leaves jq with a post-CVE-2026-33948 prefix/full-buffer mismatch on the compilation path even though the JSON parser path has already been fixed.

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-2026-41256

  • 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-2026-41256

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

  • jq Azure Linux 3.0 1.7.1-6

azure linux advisories AZL-86384

Azure Linux vulnerability data, Copyright (c) Microsoft Corporation, from https://github.com/microsoft/AzureLinuxVulnerabilityData via OSV, under the MIT licence; changed: normalised to fixed package versions per release. MIT

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-2026-41256 updated cvss 5.5

jq: embedded NUL truncates top-level jq programs loaded with -f

  • Red Hat Ansible Automation Platform 2 automation-controller, ansible-automation-platform-26/hub-rhel9, ansible-automation-platform-26/controller-rhel9 Red Hat Ceph Storage 4 jq Red Hat Enterprise Linux 8 jq Red Hat Enterprise Linux 9 jq Red Hat Enterprise Linux 10 jq Red Hat OpenShift Container Platform 4 openshift/ose-rhel-coreos-8, openshift/ose-rhel-coreos-9
    affected: workaround, no fix available “Do not process untrusted filter files using the -f flag with the jq command line JSON processor.”
  • Red Hat Hardened Images jq 1.8.2-0.1.hum1
    fixed: vendor fix “Do not process untrusted filter files using the -f flag with the jq command line JSON processor.” 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-vf2h-chrj-q3fg referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

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

Affected products

  • jqlang jq

Classification

Weakness
  • CWE-158 Improper Neutralization of Null Byte or NUL Character

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.