What is CVE-2026-40469?

CVE-2026-40469 is a critical-severity vulnerability in Fossies Gawk, classified under Integer Overflow or Wraparound. CVSS score: 9.1/10. Published 2026-07-13.

How severe is CVE-2026-40469?

Critical severity. CVSS v3 base score is 9.1 out of 10.

Integer overflow in Fossies Gawk

CVE-2026-40469

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.

Vulnerability class: Integer Overflow

Published 2026-07-13 · last modified 2026-07-14.

CVSS v3 metric

CVSS v3 base score 9.1 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:H.

EPSS exploit prediction

EPSS: 0.002 (10.8th percentile), scored 2026-10-12.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 11th percentile — 10.8% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.004 · newest: 0.002 · change: -0.001

Affected products

Fossies Gawk
GNU Gawk — versions 0

Weakness classification (CWE)

CWE-190 — Integer Overflow or Wraparound

References

cgit.git.savannah.gnu.org/cgit/gawk.git/commit/ (Patch, patch)
cert.pl/en/posts/2026/07/CVE-2026-40467 (Third Party Advisory, third-party-advisory)

Frequently asked questions

What is CVE-2026-40469?: CVE-2026-40469 is a critical-severity vulnerability in Fossies Gawk, classified under Integer Overflow or Wraparound. CVSS score: 9.1/10. Published 2026-07-13.
How severe is CVE-2026-40469?: Critical severity. CVSS v3 base score is 9.1 out of 10.