CVE-2026-40467: Use after free in gawk

Severity: high (CVSS 7.5 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.2% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-07-13 · updated 2026-10-24
Weakness: CWE-416

Description

Use After Free vulnerability has been found in "io.c" program file of gawk (do_getline_redir() routine). This issue may lead to a crash. It affects gawk in versions 5.4.0 and below.

Affected products

GNU gawk: through 5.4.0

References

https://cert.pl/en/posts/2026/07/CVE-2026-40467
https://cgit.git.savannah.gnu.org/cgit/gawk.git/commit/?id=a2d18c74109e41bec29a23098eba2e00057286d8

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