> CVE-2026-39402 [MEDIUM]

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PUBLISHED
2026-05-05 21:16
MODIFIED
2026-05-05 21:16
CVSS_SCORE V3
4.3
EPSS (Prob. Exploit)
0.14%
Top 97.2%
DATA SOURCES:
NVD đź”— 2026-05-05 CWE MITRE đź”— 2026-11-01 FIRST EPSS đź”— 2026-10-25 OSV đź”— 2026-07-26

> DESCRIPTION

lxc is a Linux container runtime. In the setuid helper lxc-user-nic, the delete path contains a logic flaw in the find_line() function that allows an unprivileged user to delete OVS-attached network interfaces belonging to other users. When lxc-user-nic delete scans its NIC database to authorize a deletion request, the interface name comparison can set the authorization flag based on a name match alone, even when the ownership, type, and link fields in that database entry belong to a different user. The vulnerable check sits after the goto next label handling, meaning it is reachable on lines where earlier ownership checks failed or were skipped. Because nothing downstream of this authorization signal re-verifies that the matched database line actually belongs to the caller, an unprivileged attacker with a valid lxc-usernet policy entry can trigger deletion of another user's OVS port on the same bridge. This is limited to multi-tenant environments using lxc-user-nic with OpenVSwitch bridges. The impact is denial of service - one tenant can repeatedly disconnect networking from containers run by another tenant on shared infrastructure. This is patched in version 7.0.0.

> 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:P/PR:L/UI:N/VC:N/VI:N/VA:N/SC:N/SI:N/SA:H/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:P/PR:L/UI:N/VC:N/VI:N/VA:N/SC:N/SI:N/SA:H/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
Low (L)
Authentifié avec compte utilisateur basique
UI (Interaction Utilisateur)
User Interaction
None (N)
Aucune interaction utilisateur nécessaire
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
None (N)
Aucune modification de données possible
A (Impact Disponibilité)
Availability Impact
None (N)
Aucune interruption de service

> RÉSUMÉ DES IMPACTS

Confidentialité
None
Aucune divulgation d'informations
Intégrité
None
Aucune modification de données possible
Disponibilité
None
Aucune interruption de service

> WEAKNESSES

CWE-863

> CWE DETAILED DESCRIPTIONS

CWE-863: Incorrect Authorization - The product performs an authorization check when an actor attempts to access a resource or perform an action, but it does not correctly perform the check.

> OSV (GOOGLE OPEN SOURCE VULNERABILITIES)

lxc lxc-user-nic insufficient ownership validation allows cross-tenant OVS port deletion

AFFECTED PACKAGES:
Unknown / Unknown
77 versions affected
ALIASES:
GHSA-3m9j-g9gc-vcvq

> HISTORIQUE DES MODIFICATIONS

Première apparition
05/05/2026 21:16
Source: NVD
đź“Š ENRICHISSEMENT 01/06/2026 06:01
CWE
Champ modifié: Description CWE
Ancienne valeur:
N/A
Nouvelle valeur:
CWE-863: Incorrect Authorization - The product performs an authorization check when an actor attempts to access a resource or perform an action, but it does not correctly perform the check.
Total des modifications: 1 Dernière mise à jour: 5 months ago

> REFERENCES

https://github.com/lxc/lxc/security/advisories/GHSA-3m9j-g9gc-vcvq
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