CVE-2026-56389

Name
CVE-2026-56389
Description
GNU Bison allows for an execution of an arbitrary program during HTML report generation due to improper handling of grammar-defined configuration variables. A grammar file can override the executable used for the XML‑to‑HTML transformation step via %define tool.xsltproc, which is accepted without restriction and passed directly to execvp(). When running bison --html on a attacker-provided grammar, this behavior allows execution of an arbitrary program with the privileges of the Bison process. Maintainers of this project were notified about this vulnerability, and fixed the issue in commit 3169c1e7a2c6acc4c59dfcf8b089896d6881925b. 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.
NVD Severity
unknown
Other trackers
Mailing lists
Exploits
Forges
GitHub (code, issues), Aports (code, issues)

References

Type URI
cvd@cert.pl https://cert.pl/en/posts/2026/07/CVE-2026-56389
cvd@cert.pl https://cgit.git.savannah.gnu.org/cgit/bison.git/
cvd@cert.pl https://cgit.git.savannah.gnu.org/cgit/bison.git/commit/?id=3169c1e7a2c6acc4c59dfcf8b089896d6881925b

Match rules

CPE URI Source package Min version Max version
cpe:2.3:a:gnu:bison:3.8.2:*:*:*:*:*:*:* bison == None == 3.8.2

Vulnerable and fixed packages

Source package Branch Version Maintainer Status
bison edge-main 3.8.2-r3 Achill Gilgenast <achill@achill.org> possibly vulnerable
bison edge-main 3.8.2-r2 Celeste <cielesti@protonmail.com> possibly vulnerable
bison edge-main 3.8.2-r1 Natanael Copa <ncopa@alpinelinux.org> possibly vulnerable
bison 3.24-main 3.8.2-r3 Achill Gilgenast <achill@achill.org> possibly vulnerable
bison 3.23-main 3.8.2-r2 Celeste <cielesti@protonmail.com> possibly vulnerable
bison 3.22-main 3.8.2-r2 Celeste <cielesti@protonmail.com> possibly vulnerable
bison 3.21-main 3.8.2-r1 Natanael Copa <ncopa@alpinelinux.org> possibly vulnerable
bison 3.20-main 3.8.2-r1 Natanael Copa <ncopa@alpinelinux.org> possibly vulnerable
bison 3.19-main 3.8.2-r1 Natanael Copa <ncopa@alpinelinux.org> possibly vulnerable