Nixpkgs security tracker

Login with GitHub

Details of issue NIXPKGS-2026-2317

NIXPKGS-2026-2317
published 10 hours ago
Arbitrary Command Execution in GNU Bison
Permalink CVE-2026-56389
6.8 MEDIUM
  • CVSS version (CVSS): 4.0
  • Attack Vector (AV): Local (L)
  • Attack Complexity (AC): Low (L)
  • Attack Requirement (AT): None (N)
  • Privileges Required (PR): None (N)
  • User Interaction (UI): Active (A)
  • Vulnerable System Impact Confidentiality (VC): None (N)
  • Vulnerable System Impact Integrity (VI): High (H)
  • Vulnerable System Impact Availability (VA): Low (L)
  • Subsequent System Impact Confidentiality (SC): Low (L)
  • Subsequent System Impact Integrity (SI): Low (L)
  • Subsequent System Impact Availability (SA): Low (L)
  • Modified Attack Vector (MAV): Local (L)
  • Modified Attack Complexity (MAC): Low (L)
  • Modified Attack Requirement (MAT): None (N)
  • Modified Privileges Required (MPR): None (N)
  • Modified User Interaction (MUI): Active (A)
  • Modified Vulnerable System Impact Confidentiality (MVC): None (N)
  • Modified Vulnerable System Impact Integrity (MVI): High (H)
  • Modified Vulnerable System Impact Availability (MVA): Low (L)
  • Modified Subsequent System Impact Confidentiality (MSC): Low (L)
  • Modified Subsequent System Impact Integrity (MSI): Low (L)
  • Modified Subsequent System Impact Availability (MSA): Low (L)
  • Safety (S): Not Defined (X)
  • Automatable (AU): Not Defined (X)
  • Recovery (R): Not Defined (X)
  • Value Density (V): Not Defined (X)
  • Vulnerability Response Effort (RE): Not Defined (X)
  • Provider Urgency (U): Not Defined (X)
  • Confidentiality Req. (CR): Not Defined (X)
  • Integrity Req. (IR): Not Defined (X)
  • Availability Req. (AR): Not Defined (X)
  • Exploit Maturity (E): Not Defined (X)
updated 10 hours ago by @LeSuisse Activity log
  • Created suggestion 1 day, 4 hours ago
  • @LeSuisse ignored package bisoncpp 10 hours ago
  • @LeSuisse accepted 10 hours ago
  • @LeSuisse published on GitHub 10 hours ago
Arbitrary Command Execution in GNU Bison

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.

Affected products

Bison
  • ==3.8.2

Matching in nixpkgs

pkgs.bison

Yacc-compatible parser generator

Ignored packages (1)