Vulnerability · Published Jul 13, 2026 · Assigned by CERT-PL
CVE-2026-40553Stack-based buffer overflow in gawk
Medium 5.1
In plain English
A medium-severity stack buffer overflow in gawk from GNU. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.3% (higher than 22% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Official description
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.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| AlmaLinux:10 | gawk | 5.3.0-6.el10_2.1 | ALSA-2026:73429 |
| AlmaLinux:9 | gawk | 5.1.0-6.el9_8.1 | ALSA-2026:73512 |
| AlmaLinux:10 | gawk-all-langpacks | 5.3.0-6.el10_2.1 | ALSA-2026:73429 |
| AlmaLinux:9 | gawk-all-langpacks | 5.1.0-6.el9_8.1 | ALSA-2026:73512 |
| Debian:12 | gawk | no fix listed | DEBIAN-CVE-2026-40553 |
| Debian:13 | gawk | no fix listed | DEBIAN-CVE-2026-40553 |
| Debian:14 | gawk | no fix listed | DEBIAN-CVE-2026-40553 |
| Rocky Linux:10 | gawk | 0:5.3.0-6.el10_2.1 | RLSA-2026:73429 |
| Rocky Linux:9 | gawk | 0:5.1.0-6.el9_8.1 | RLSA-2026:73512 |
| Ubuntu:22.04:LTS | gawk | 1:5.1.0-1ubuntu0.2 | USN-8588-1 |
| Ubuntu:24.04:LTS | gawk | 1:5.2.1-2ubuntu0.1 | USN-8588-1 |
| Ubuntu:26.04:LTS | gawk | 1:5.3.2-1ubuntu1.1 | USN-8588-1 |
| Ubuntu:26.04:LTS | gawk | 1:5.3.2-1ubuntu1.1 | UBUNTU-CVE-2026-40553 |
Affected products (as reported)
Weakness: CWE-121 · Vector: 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