PT-2026-65778 · Gnu · Bison

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CVE-2026-56390

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Published

2026-07-29

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Updated

2026-08-24

CVSS v4.0

6.8

Medium

VectorAV:L/AC:L/AT:N/PR:N/UI:A/VC:N/VI:H/VA:L/SC:L/SI:L/SA:L/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
Name of the Vulnerable Software and Affected Versions GNU Bison version 3.8.2
Description GNU Bison improperly handles grammar-defined output paths. Grammar directives such as %output and %header allow specifying file paths that 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, which could lead to the overwriting of existing files accessible to the Bison process.
Recommendations At the moment, there is no information about a newer version that contains a fix for this vulnerability.
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Weakness Enumeration

Related Identifiers

AZL-94136
CVE-2026-56390
ECHO-C721-9C49-EC13
JLSEC-2026-1346
OESA-2026-3304
OESA-2026-3305
OESA-2026-3306
OESA-2026-3307

Affected Products

Bison