CVE-2026-40468 — Heap buffer overflow in gawk

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LOW

Heap buffer overflow in gawk

Published Jul 13, 2026

2.1

LOW

CVSS 4.0

EPSS 0.35%

Description

Integer overflow vulnerability has been found in "builtin.c" program file of gawk. This issue may lead to memory exhaustion on the hosting operating system and could be used to overwrite gawk heap metadata and objects with attacker-controlled bytes. It affects gawk in versions 5.4.0 and below.

Affected products

Vendor GNU Product Gawk Default
unaffected
- Version
  0
  Status
  affected
  Constraints
  <=5.4.0

Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).

Vendor

Product

Default status

Versions

GNU

Gawk

unaffected

Version	Status	Constraints
0	affected	<=5.4.0

Red Hat Hardened Images

gawk-main-5.4.0-3.1.hum1

Fixed · RHSA-2026:40041
Red Hat Hardened Images

gawk-main-5.4.1-1.hum1

Fixed · RHSA-2026:49661
Red Hat Enterprise Linux 10

gawk

Affected
Red Hat Enterprise Linux 6

gawk

Out of support scope
Red Hat Enterprise Linux 7

gawk

Affected
Red Hat Enterprise Linux 8

gawk

Affected
Red Hat Enterprise Linux 9

gawk

Affected
Red Hat OpenShift Container Platform 4

openshift/ose-rhel-coreos-8

Affected
Red Hat OpenShift Container Platform 4

openshift/ose-rhel-coreos-9

Affected

Product	Package	State	Advisory
Red Hat Hardened Images	gawk-main-5.4.0-3.1.hum1	Fixed	RHSA-2026:40041
Red Hat Hardened Images	gawk-main-5.4.1-1.hum1	Fixed	RHSA-2026:49661
Red Hat Enterprise Linux 10	gawk	Affected	n/a
Red Hat Enterprise Linux 6	gawk	Out of support scope	n/a
Red Hat Enterprise Linux 7	gawk	Affected	n/a
Red Hat Enterprise Linux 8	gawk	Affected	n/a
Red Hat Enterprise Linux 9	gawk	Affected	n/a
Red Hat OpenShift Container Platform 4	openshift/ose-rhel-coreos-8	Affected	n/a
Red Hat OpenShift Container Platform 4	openshift/ose-rhel-coreos-9	Affected	n/a

Remediation

Red Hat statement

Moderate: An integer overflow vulnerability in gawk's builtin.c could allow a local attacker to cause memory exhaustion and overwrite heap metadata. This could lead to system instability or a denial of service on affected Red Hat products, requiring local access to execute a malicious gawk script.

Red Hat mitigation

Do not execute untrusted awk scripts or process untrusted inputs that could trigger oversized calculations in builtin.c.

Metrics

0.35% 0.00353

Estimated probability of exploitation in the wild in the next 30 days (FIRST EPSS). As of Oct 1, 2026.

EPSS probability 0.00353

Score over time

Jul–Oct 2026

EPSS v5

Percentile over time

EPSS v5

Table of values (2 key points)

Flat stretches are collapsed; showing up to 120 newest points.

Date	Score	Percentile	Model
Oct 1, 2026	0.35% (0.00353)	26.58th	v5 (v2026.06.15)
Jul 14, 2026	0.20% (0.00201)	10.07th	v5 (v2026.06.15)

Weaknesses (1)

CWE-190

Integer Overflow

References (6)

https://access.redhat.com/security/cve/CVE-2026-40468
Vendor Advisory
https://bugzilla.redhat.com/show_bug.cgi?id=2499655
Issue Tracking
https://cert.pl/en/posts/2026/07/CVE-2026-40467
third-party-advisoryThird Party Advisory
https://cgit.git.savannah.gnu.org/cgit/gawk.git/commit/?id=062f2f2581b991362c046f7f2e238ffa34e6f8c7
patch
https://nvd.nist.gov/vuln/detail/CVE-2026-40468
https://www.cve.org/CVERecord?id=CVE-2026-40468

Link	Providers	Tags
https://access.redhat.com/security/cve/CVE-2026-40468		Vendor Advisory
https://bugzilla.redhat.com/show_bug.cgi?id=2499655		Issue Tracking
https://cert.pl/en/posts/2026/07/CVE-2026-40467		third-party-advisoryThird Party Advisory
https://cgit.git.savannah.gnu.org/cgit/gawk.git/commit/?id=062f2f2581b991362c046f7f2e238ffa34e6f8c7		patch
https://nvd.nist.gov/vuln/detail/CVE-2026-40468
https://www.cve.org/CVERecord?id=CVE-2026-40468