CVE-2026-52931
CriticalCVSS 9.8Exploitation Probability (EPSS)
Low risk32th percentile — higher than 32% of all known CVEs
Summary
In the Linux kernel, a vulnerability was found in the batman-adv tp_meter module. Functions batadv_tp_recv_ack() and batadv_tp_stop() can be called for tp_vars in the BATADV_TP_RECEIVER role, leading to reading uninitialized sender-only fields and causing undefined behavior. This can be triggered by sending a malicious ACK packet to a node acting as a receiver in an ongoing tp_meter session.
Risk Assessment
An attacker can remotely trigger undefined behavior in the Linux kernel on devices using batman-adv, potentially leading to system crashes or other unforeseen consequences.
Recommendation
Immediately update the Linux kernel to a version containing the fix that adds a role check for tp_vars before accessing sender fields.
Original NVD description (English source)
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.