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Fencer Vulns
high 7.5

CVE-2026-40467 json

Use after free in gawk

published 2026-07-13 3 mo ago modified 2026-10-24 15 d ago also EUVD-2026-43492 , JLSEC-2026-785

cvss
7.5
version 3.1, NVD
cisa kev
Not listed
not in CISA's catalog
epss
0.2%
EPSS 0.2% chance of exploitation in 30 days, percentile 11%
public exploits
0
none known

Summary

Use After Free vulnerability has been found in "io.c" program file of gawk (do_getline_redir() routine). This issue may lead to a crash. It affects gawk in versions 5.4.0 and below.

Patch / fix

  • julia gawk_jll 5.4.1+0
  • gawk Ubuntu 22.04 LTS 1:5.1.0-1ubuntu0.2
  • gawk Ubuntu 24.04 LTS 1:5.2.1-2ubuntu0.1
  • gawk Ubuntu 26.04 LTS 1:5.3.2-1ubuntu1.1
  • gawk Ubuntu Pro 14.04 LTS 1:4.0.1+dfsg-2.1ubuntu2+esm2
  • gawk Ubuntu Pro 16.04 LTS 1:4.1.3+dfsg-0.1ubuntu0.1~esm2
  • gawk Ubuntu Pro 18.04 LTS 1:4.1.4+dfsg-1ubuntu0.1~esm2
  • gawk Ubuntu Pro 20.04 LTS 1:5.0.1+dfsg-1ubuntu0.1+esm1

ubuntu advisories UBUNTU-CVE-2026-40467

Ubuntu security data © Canonical Ltd., from https://github.com/canonical/ubuntu-security-notices via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

  • gawk RHEL 8 4.2.1-5.el8_10
  • gawk RHEL 9 5.1.0-6.el9_8.1
  • gawk-all-langpacks RHEL 9 5.1.0-6.el9_8.1
  • gawk RHEL 10.2 5.3.0-6.el10_2.1
  • gawk-all-langpacks RHEL 10.2 5.3.0-6.el10_2.1
  • gawk hummingbird 1 5.4.1-1.hum1
  • gawk-all-langpacks hummingbird 1 5.4.1-1.hum1
  • gawk hummingbird 1 5.4.0-3.1.hum1

red hat advisories RHSA-2026:73511RHSA-2026:73512RHSA-2026:73429RHSA-2026:49661RHSA-2026:40041

  • gawk SLE Module for Basesystem 15 SP7, SLE Micro 5.5, SLE Micro 5.4 +1 more 4.2.1-150000.3.6.1
  • gawk Linux Micro 6.0 5.3.0-2.1
  • gawk SLES 16.0, Linux Micro 6.2, SLES for SAP applications 16.0 5.3.2-160000.3.1

suse advisories SUSE-SU-2026:3455-1SUSE-SU-2026:23042-1SUSE-SU-2026:22767-1SUSE-SU-2026:22831-1

  • gawk openSUSE Leap 16.0 5.3.2-160000.3.1

opensuse advisories openSUSE-SU-2026:21393-1

  • gawk AlmaLinux 10 5.3.0-6.el10_2.1
  • gawk-all-langpacks AlmaLinux 10 5.3.0-6.el10_2.1
  • gawk AlmaLinux 8 4.2.1-5.el8_10
  • gawk AlmaLinux 9 5.1.0-6.el9_8.1
  • gawk-all-langpacks AlmaLinux 9 5.1.0-6.el9_8.1

almalinux advisories ALSA-2026:73429ALSA-2026:73511ALSA-2026:73512

  • gawk Rocky Linux 8 4.2.1-5.el8_10
  • gawk Rocky Linux 10 5.3.0-6.el10_2.1
  • gawk Rocky Linux 9 5.1.0-6.el9_8.1

rocky linux advisories RLSA-2026:73511RLSA-2026:73429RLSA-2026:73512

  • gawk Azure Linux 3.0 5.2.2-2

azure linux advisories AZL-92292

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-2026-40467 updated cvss 4.0

gawk: gawk: Denial of Service due to Use After Free vulnerability in io.c

  • Red Hat Enterprise Linux 6 gawk
    affected: workaround, no fix planned “Out of support scope”
  • Red Hat Enterprise Linux 7 gawk Red Hat OpenShift Container Platform 4 openshift/ose-rhel-coreos-8 Red Hat OpenShift Container Platform 5 openshift/ose-rhel-coreos-9
    affected: workaround, no fix available
  • Red Hat Cost Management On-Premise 1 costmanagement/costmanagement-ui-rhel10 1791460851
    fixed: vendor fix RHSA-2026:79357
  • Red Hat Enterprise Linux AppStream (v. 9) gawk-all-langpacks 5.1.0-6.el9_8.1
    fixed: vendor fix RHSA-2026:73512
  • Red Hat Enterprise Linux AppStream (v. 10) gawk-all-langpacks 5.3.0-6.el10_2.1
    fixed: vendor fix RHSA-2026:73429
  • Red Hat Enterprise Linux BaseOS (v. 8) gawk 4.2.1-5.el8_10
    fixed: vendor fix RHSA-2026:73511
  • Red Hat Enterprise Linux BaseOS (v. 9) gawk 5.1.0-6.el9_8.1
    fixed: vendor fix RHSA-2026:73512
  • Red Hat Enterprise Linux BaseOS (v. 10) gawk 5.3.0-6.el10_2.1
    fixed: vendor fix RHSA-2026:73429
show 4 more
  • Red Hat Hardened Images gawk 5.4.1-1.hum1, gawk 5.4.0-3.1.hum1, gawk-all-langpacks 5.4.1-1.hum1, gawk-all-langpacks 5.4.0-3.1.hum1
    fixed: vendor fix RHSA-2026:40041
  • Red Hat OpenShift Container Platform 4.22 rhcos 4.22.9.8.202610241758
    fixed: vendor fix RHSA-2026:89197
  • Red Hat Update Infrastructure 5 rhui5/cds-rhel9 1791978528, rhui5/rhua-rhel9 1791978693, rhui5/haproxy-rhel9 1791978528, rhui5/installer-rhel9 1791964013, rhui5/cds-kubernetes-rhel9 1791978534
    fixed: vendor fix RHSA-2026:82939
  • Red Hat OpenShift AI (RHOAI) rhoai/odh-kserve-controller-rhel9, rhoai/odh-model-serving-api-rhel9, rhoai/odh-llama-stack-k8s-operator-rhel9, rhoai/odh-kserve-llmisvc-controller-rhel9
    not affected: vulnerable code not present

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
none
Automatable
no
Technical impact
partial
Assessed
3 mo ago

Exploit prediction

0.21% chance of exploitation in the next 30 days, higher than 11% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CNA 4.0 5.1 CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N
CNA 4.0 5.1 CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
NVD 3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
OSV 3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Affected packages

ecosystem package affected fixed in
julia gawk_jll
<5.4.1+0
5.4.1+0

Affected products

  • GNU gawk

Classification

Weakness

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.