CVE-2026-56390

Sažetak

GNU Bison improperly handles grammar‑defined output paths. Grammar directives such as %output and %header allow specifying file paths, which are accepted without restriction and override caller‑supplied output options. When processing attacker-supplied grammar, this behavior allows directing generated files to arbitrary writable locations on the filesystem, potentially overwriting existing files accessible to the Bison process. Maintainers of this project were notified about this vulnerability, and fixed the issue in commit 8d101c19d4d9aaedf83a448c925513742d4efcf0. However, they did not provide vulnerable version range. Version 3.8.2 was tested and confirmed as vulnerable, other versions were not tested but might also be vulnerable.

Reference

CVSS

Base:	6.3
Impact:	4.0
Exploitability:	1.8

Pristup

Vektor	Složenost	Autentikacija
LOCAL	LOW	NONE

Impact

Povjerljivost	Cjelovitost	Dostupnost
NONE	HIGH	NONE

CVSS vektor

CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:C/C:N/I:H/A:N

Zadnje važnije ažuriranje

24-08-2026 - 16:10

Objavljeno

29-07-2026 - 11:16