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Fencer Vulns
high 7.5

CVE-2026-40553 json

Stack-based buffer overflow in gawk

published 2026-07-13 3 mo ago modified 2026-10-24 15 d ago also EUVD-2026-43495 , JLSEC-2026-788

cvss
7.5
version 3.1, NVD
cisa kev
Not listed
not in CISA's catalog
epss
0.3%
EPSS 0.3% chance of exploitation in 30 days, percentile 21%
public exploits
0
none known

Summary

Buffer overflow vulnerability has been found in "extension/readdir.c" program file of gawk (ftype() routine). This issue could be used to crash the program and potentially to achieve code execution, although the latter has not been confirmed to be feasible. It affects gawk in versions 5.4.0 and below.

Patch / fix

  • julia gawk_jll 5.4.1+0
  • gawk Ubuntu 26.04 LTS 1:5.3.2-1ubuntu1.1

ubuntu advisories UBUNTU-CVE-2026-40553

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 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
  • gawk-all-langpacks hummingbird 1 5.4.0-3.1.hum1

red hat advisories RHSA-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 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-2026:73512

  • 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-2026:73429RLSA-2026:73512

  • gawk Azure Linux 3.0 5.2.2-2

azure linux advisories AZL-92283

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-2026-40553 updated cvss 6.2

gawk: Gawk: Buffer overflow in ftype() routine may lead to code execution or denial of service

  • Red Hat Enterprise Linux 6 gawk
    affected: workaround, no fix planned “Out of support scope”
  • 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. 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
  • 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 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
show 4 more
  • Red Hat Enterprise Linux 7 gawk
    not affected: vulnerable code not present
  • Red Hat Enterprise Linux 8 gawk
    not affected: vulnerable code not in execute path
  • 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 OpenShift Container Platform 4 openshift/ose-rhel-coreos-8, openshift/ose-rhel-coreos-9 Red Hat OpenShift Container Platform 5 openshift/ose-rhel-coreos-9
    not affected: vulnerable code not in execute path

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

0.29% chance of exploitation in the next 30 days, higher than 21% 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:L/VA:L/SC:L/SI:L/SA:L
CNA 4.0 5.1 CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:L/SC:L/SI:L/SA:L/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
  • CWE-121 Stack-based Buffer Overflow

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.