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Fencer Intel
critical 9.1

CVE-2026-40469 json

Heap buffer overflow in gawk

published 3mo ago modified 16d ago also EUVD-2026-43494 , JLSEC-2026-787

cvss
9.1
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

Integer overflow vulnerability has been found in "builtin.c" program file of gawk (do_sub() routine). This issue could be used to overwrite gawk heap metadata and objects causing the program to crash. It affects 32-bit builds of 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-2026-40469

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 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-2026:49661RHSA-2026:40041

Is CVE-2026-40469 in your dependencies? Fencer shows which of your repositories are affected as soon as an advisory lands, and opens the fix as a pull request.

Check with Fencer

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-2026-40469 updated cvss 2.8

gawk: gawk: Denial of Service due to integer overflow

  • Red Hat Enterprise Linux 6 gawk
    affected: workaround, no fix planned “Out of support scope”
  • 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 Enterprise Linux 7 gawk Red Hat Enterprise Linux 8 gawk Red Hat Enterprise Linux 9 gawk, gawk-all-langpacks Red Hat Enterprise Linux 10 gawk 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 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
3mo ago

Exploit prediction

0.21% chance of exploitation in the next 30 days, higher than 11% of all scored CVEs (FIRST EPSS, 2026-11-09).

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 9.1 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:H
OSV 3.1 9.1 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/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-190 Integer Overflow or Wraparound

References

Sources

Fencer Intel 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.