CVE-2026-56390: Arbitrary Output Location Change in GNU Bison
GNU · Bison
Vendor fix available · Affected: GNU Bison · Exploitation: unlikely (under 1%)
Not in CyberSIXT coverage yet: no article names this CVE. This page shows the public record.
Higher than 2% of scored CVEs
DescriptionCVE.org
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.
Affected products1
From the CVE record. A product or version that is not listed is unknown, not unaffected.
- GNU · Bison3.8.2
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No CyberSIXT article names CVE-2026-56390 yet, so there is no coverage timeline, action brief or change log for it. Everything on this page comes from the public CVE record, CISA KEV, EPSS and the nuclei template index. Search the archive or see the CVEs in the news.