PT-2026-36995 · Lxc · Lxc

Snoopysecurity · Published 2026-05-04 · Updated 2026-05-12 · CVE-2026-39402

Positive Technologies (AI Summary)

CVSS v3.1

6.5

Medium

Base vector

AV:L/AC:L/PR:L/UI:N/S:C/C:N/I:N/A:H

Name of the Vulnerable Software and Affected Versions lxc versions prior to 7.0.0

Description A logic flaw in the find line() function of the lxc-user-nic setuid helper allows an unprivileged user to delete OVS-attached network interfaces belonging to other users. When scanning the NIC database to authorize a deletion request, the interface name comparison may set the authorization flag based solely on a name match, ignoring ownership, type, and link fields. This occurs because the check is reachable after the goto next label handling, and subsequent processes do not re-verify that the matched entry belongs to the caller. In multi-tenant environments using OpenVSwitch bridges, an attacker with a valid lxc-usernet policy entry can trigger the deletion of another user's OVS port on the same bridge, resulting in a denial of service by repeatedly disconnecting networking from other tenants' containers.

Recommendations Update to version 7.0.0.

Exploit

Fix

DoS

Incorrect Authorization

Weakness Enumeration

CWE-863

Related Identifiers

CVE-2026-39402

OPENSUSE-SU-2026:10678-1

Affected Products

Lxc

References · 14

• 🔥 https://github.com/lxc/lxc/security/advisories/GHSA-3m9j-g9gc-vcvq · Exploit
• https://osv.dev/vulnerability/DEBIAN-CVE-2026-39402 · Vendor Advisory
• https://security-tracker.debian.org/tracker/CVE-2026-39402 · Vendor Advisory
• https://osv.dev/vulnerability/UBUNTU-CVE-2026-39402 · Vendor Advisory
• https://nvd.nist.gov/vuln/detail/CVE-2026-39402 · Security Note
• https://ubuntu.com/security/CVE-2026-39402 · Vendor Advisory
• https://osv.dev/vulnerability/openSUSE-SU-2026:10678-1 · Vendor Advisory
• https://cve.org/CVERecord?id=CVE-2026-39402 · Security Note
• https://github.com/lxc/lxc/pull/4678 · Note
• https://t.me/CVEtracker/52796 · Telegram Post
• https://twitter.com/infoflowcloud/status/2051779350417072284 · Twitter Post
• https://twitter.com/CVEnew/status/2051777784939246018 · Twitter Post
• https://suse.com/security/cve/CVE-2026-39402 · Note
• https://t.me/cveNotify/163251 · Telegram Post