Critical severity · published Jul 13, 2026
CVE-2026-40469
Heap buffer overflow in gawk
9.1
CVSS
0.2%
EPSS
No
On KEV
Description
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.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:H
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Confidentiality
None
Integrity
High
Availability
High
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.2% · higher than 12% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
GA
gawk · GNU
through 5.4.0 · source: vendor, NVD
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-40469
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-40469
Third Party Advisory
https://cert.pl/en/posts/2026/07/CVE-2026-40467
Patch
https://cgit.git.savannah.gnu.org/cgit/gawk.git/commit/?id=ae1b2d508f46913269a9e62aceda3636afe8147b
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