CVE-2026-52931

Updated on 24 Jun 2026

Severity

9.8 Critical severity

Details

CVSS score
9.8
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Overview

About vulnerability

In the Linux kernel, the following vulnerability has been resolved:

batman-adv: tp_meter: avoid use of uninit sender vars

batadv_tp_recv_ack() and batadv_tp_stop() are only valid for tp_vars in the BATADV_TP_SENDER role. When called with a BATADV_TP_RECEIVER role, it proceeds to read sender-only members that were never initialized, leading to undefined behavior.

This can be triggered when a node that is currently acting as a receiver in an ongoing tp_meter session receives a malicious ACK packet.

Guard against this by checking tp_vars->role immediately after the lookup and bailing out if it is not BATADV_TP_SENDER, before any of those members are accessed.

Details

Affected product:
Ubuntu 20.04 ELS
Affected packages:
linux-meta @ 5.4.0 (+1 more)

KernelCare state

Live-patch status from KernelCare for each operating system.

Operating system Status Covered kernels
Debian 11 Planned
Debian 11 cloud Planned
Debian 12 Planned
Ubuntu 22.04 Planned