CVE-2026-74255
CriticalCVSS 9.8Exploitation Probability (EPSS)
Low risk7th percentile - higher than 7% of all known CVEs
Summary
In the Linux kernel, the tipc_l2_send_msg() function has a use-after-free (UAF) vulnerability. The issue arises because tipc_disable_l2_media() calls synchronize_net() while the media_ptr pointer is still valid, allowing concurrent RCU readers to obtain the device pointer after synchronization, and then the device can be freed while still in use.
Risk Assessment
Risk of use-after-free exploitation could lead to system crash, privilege escalation, or arbitrary code execution in kernel context.
Recommendation
Apply the Linux kernel update containing the fix for CVE-2026-74255.
Original NVD description (English source)
In the Linux kernel, the following vulnerability has been resolved: tipc: fix UAF in tipc_l2_send_msg() Syzbot reported a slab-use-after-free in ipvlan_hard_header() when called from tipc_l2_send_msg(). The root cause is that tipc_disable_l2_media() calls synchronize_net() while b->media_ptr is still valid. This allows concurrent RCU readers to obtain the device pointer after synchronize_net() has finished. The pointer is cleared later in bearer_disable(), but without any subsequent synchronization, allowing the device to be freed while still in use by readers. Fix this by clearing b->media_ptr in tipc_disable_l2_media() before calling synchronize_net(). This is safe to do now because the call order in bearer_disable() was reversed in 0d051bf93c06 ("tipc: make bearer packet filtering generic") to call tipc_node_delete_links() (which needs the pointer) before disable_media(). https: //lore.kernel.org/netdev/[email protected]/T/#u