Junglewise Threat Intelligence

CVE-2026-52993: Linux Kernel double-free in tipc_buf_append

CVE-2026-52993 · Severity: info · CVSS 0 · Published 2026-06-24

Vendors: Linux.

Executive brief

A vulnerability in the Linux kernel's Transparent Inter-Process Communication (TIPC) protocol could allow a remote attacker to cause a system crash. The issue occurs when the system processes specifically formatted network messages, leading to a memory management error. This can result in a denial-of-service condition where the affected server or device stops functioning.

Technical details

A double-free vulnerability exists in net/tipc/msg.c within the tipc_buf_append() function. The root cause is that tipc_msg_validate() may reallocate a socket buffer (skb) and free the original, but tipc_buf_append() maintained a stale pointer to the original buffer in its local variables. If validation subsequently fails, the error handling path attempts to free the already-freed original pointer. An attacker can trigger this by sending TIPC messages that fail validation after triggering a reallocation. Patches have been released across multiple stable kernel branches to ensure the headbuf pointer is correctly updated after validation.

Affected products

  • Linux Linux 4.15 to 6.13

Timeline

  • 2026-06-24: advisory
  • 2026-06-24: disclosed

References