Vulnerability Description
In the Linux kernel, the following vulnerability has been resolved: tipc: fix double-free in tipc_buf_append() tipc_msg_validate() can potentially reallocate the skb it is validating, freeing the old one. In tipc_buf_append(), it was being called with a pointer to a local variable which was a copy of the caller's skb pointer. If the skb was reallocated and validation subsequently failed, the error handling path would free the original skb pointer, which had already been freed, leading to double-free. Fix this by checking if head now points to a newly allocated reassembled skb. If it does, reassign *headbuf for later freeing operations.
CVSS Score
CRITICAL
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Linux | Linux Kernel | >= 4.15, < 5.10.258 |
Related Weaknesses (CWE)
References
- https://git.kernel.org/stable/c/0274f24485fc38032d4093e463dc3ff5c7a667c9Patch
- https://git.kernel.org/stable/c/1d5e589055880fae229e229e1929e087dbe08cf3Patch
- https://git.kernel.org/stable/c/29940fff14110ca48c5ccc168d121665b51bb778Patch
- https://git.kernel.org/stable/c/4d104882bc815d4ec666ace9155f5f52715879a6Patch
- https://git.kernel.org/stable/c/4ee4deadaae7cb2e3d53af0fc889cf92a73413c0Patch
- https://git.kernel.org/stable/c/a438975a6dcdbd70865978c021650d1485586f0bPatch
- https://git.kernel.org/stable/c/d293ca716e7d5dffdaecaf6b9b2f857a33dc3d3aPatch
- https://git.kernel.org/stable/c/d3556656c6daebf8def751c7e71d11dd0a180d24Patch
- https://access.redhat.com/errata/RHSA-2026:45115
- https://access.redhat.com/errata/RHSA-2026:45116
- https://access.redhat.com/errata/RHSA-2026:47017
- https://access.redhat.com/errata/RHSA-2026:49212
- https://access.redhat.com/security/cve/CVE-2026-52993Third Party Advisory
- https://bugzilla.redhat.com/show_bug.cgi?id=2492437Third Party Advisory
- https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-52993.jsonThird Party Advisory
FAQ
What is CVE-2026-52993?
CVE-2026-52993 is a vulnerability with a CVSS score of 9.8 (CRITICAL). In the Linux kernel, the following vulnerability has been resolved: tipc: fix double-free in tipc_buf_append() tipc_msg_validate() can potentially reallocate the skb it is validating, freeing the ol...
How severe is CVE-2026-52993?
CVE-2026-52993 has been rated CRITICAL with a CVSS base score of 9.8/10. This is considered a critical vulnerability requiring immediate attention.
Is there a patch for CVE-2026-52993?
Check the references section above for vendor advisories and patch information. Affected products include: Linux Linux Kernel.