CVE-2026-89951: Linux

High severity, CVSS 8.8. EPSS: 0.4% chance of exploitation in the next 30 days.

In the Linux kernel, the following vulnerability has been resolved: batman-adv: fix stale receive device on merged fragments Fragment reassembly reuses the skb from the highest-numbered buffered fragment as the merged packet. When that fragment was received on a hard interface which is deleted before the chain completes, the merged skb can re-enter the receive path with a stale skb->dev and skb_iif. batadv_batman_skb_recv() passes such merged packets through the normal receive handlers again. DAT and bridge loop avoidance both derive the ARP header length from skb->dev, so they can dereference the freed net_device before the packet reaches the local mesh interface. Refresh the receive device metadata from the current receive device before running the packet handlers. This keeps internally reinjected merged fragments consistent with the normal receive path after hard interface teardown.

Affected products

• Linux Linux: from 3.13, before 5.10.270 (fixed in 5.10.270); from 5.11, before 5.15.221 (fixed in 5.15.221); from 5.16, before 6.1.188 (fixed in 6.1.188); from 6.2, before 6.6.157 (fixed in 6.6.157); from 6.7, before 6.12.110 (fixed in 6.12.110); from 6.13, before 6.18.51 (fixed in 6.18.51); …

Published 2026-09-16. Last modified 2026-09-16.