> CVE-2026-56389 [MEDIUM]

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PUBLISHED
2026-07-29 11:16
MODIFIED
2026-07-29 11:16
CVSS_SCORE V3
6.8
EPSS (Prob. Exploit)
0.22%
Top 87.7%
DATA SOURCES:
NVD đź”— 2026-07-29 CWE MITRE đź”— 2026-11-01 FIRST EPSS đź”— 2026-10-25 MSRC đź”— 2026-11-02

> 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.

> AFFECTED_PRODUCTS

ℹ️ Aucun produit affecté n'a encore été publié par NVD pour cette CVE.

> CVSS V3 METRICS

CVSS_VECTOR
CVSS:4.0/AV: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

> MÉTRIQUES CVSS DÉTAILLÉES

CVSS:4.0/AV: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
Métrique Valeur Interprétation
AV (Vecteur d'Attaque)
Attack Vector
Local (L)
Exploit nécessite un accès local au système
AC (Complexité d'Attaque)
Attack Complexity
Low (L)
Peu de conditions requises pour exploiter
PR (Privilèges Requis)
Privileges Required
None (N)
Aucune authentification requise
UI (Interaction Utilisateur)
User Interaction
Required (R)
Nécessite une action utilisateur (clic lien, ouverture fichier, etc.)
S (Périmètre)
Scope
Unchanged (U)
Impact reste dans le périmètre du composant compromis
C (Impact Confidentialité)
Confidentiality Impact
None (N)
Aucune divulgation d'informations
I (Impact Intégrité)
Integrity Impact
High (H)
Modification totale des données possible
A (Impact Disponibilité)
Availability Impact
Low (L)
Interruption partielle du service possible

> RÉSUMÉ DES IMPACTS

Confidentialité
None
Aucune divulgation d'informations
Intégrité
High
Modification totale des données possible
Disponibilité
Low
Interruption partielle du service possible

> WEAKNESSES

CWE-78

> CWE DETAILED DESCRIPTIONS

CWE-78: Improper Neutralization of Special Elements used in an OS Command - The product constructs all or part of an OS command using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify the intended OS command before it is sent to a downstream component.

> HISTORIQUE DES MODIFICATIONS

Première apparition
29/07/2026 11:16
Source: NVD
📊 ENRICHISSEMENT 01/11/2026 06:59
CWE
Champ modifié: Description CWE
Ancienne valeur:
CWE-78: Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection') - The product constructs all or part of an OS command using externally-influenced input from an upstr...
Nouvelle valeur:
CWE-78: Improper Neutralization of Special Elements used in an OS Command - The product constructs all or part of an OS command using externally-influenced input from an upstream component, but it doe...
📊 ENRICHISSEMENT 01/08/2026 06:01
CWE
Champ modifié: Description CWE
Ancienne valeur:
N/A
Nouvelle valeur:
CWE-78: Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection') - The product constructs all or part of an OS command using externally-influenced input from an upstr...
Total des modifications: 2 Dernière mise à jour: 4 days ago

> REFERENCES

https://cert.pl/en/posts/2026/07/CVE-2026-56389
https://cgit.git.savannah.gnu.org/cgit/bison.git/
https://cgit.git.savannah.gnu.org/cgit/bison.git/commit/?id=3169c1e7a2c6acc4c59d...
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