CVE-2026-43011
CriticalCVSS 9.8Exploitation Probability (EPSS)
Low risk40th percentile - higher than 40% of all known CVEs
Summary
In the Linux kernel X.25 stack, a double free of a socket buffer (skb) was discovered. When x25_queue_rx_frame fails to allocate memory, it frees the skb and returns an error, but the caller x25_backlog_rcv also attempts to free the same skb, causing a double free.
Risk Assessment
Double free memory corruption can lead to kernel structure damage, potentially allowing a local attacker to cause a denial of service (DoS) or escalate privileges.
Recommendation
Immediately apply the patch from the official Linux kernel repository for CVE-2026-43011 or update the system to a kernel version containing the fix.
Original NVD description (English source)
In the Linux kernel, the following vulnerability has been resolved: net/x25: Fix potential double free of skb When alloc_skb fails in x25_queue_rx_frame it calls kfree_skb(skb) at line 48 and returns 1 (error). This error propagates back through the call chain: x25_queue_rx_frame returns 1 | v x25_state3_machine receives the return value 1 and takes the else branch at line 278, setting queued=0 and returning 0 | v x25_process_rx_frame returns queued=0 | v x25_backlog_rcv at line 452 sees queued=0 and calls kfree_skb(skb) again This would free the same skb twice. Looking at x25_backlog_rcv: net/x25/x25_in.c:x25_backlog_rcv() { ... queued = x25_process_rx_frame(sk, skb); ... if (!queued) kfree_skb(skb); }