CVE-2026-52993
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.
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (0.37%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
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 3.1
- 9.8 CRITICALCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
- EPSS
- 0.37% probability · 30th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-415, CWE-763
- Affected
- linux/linux kernel
- Source
- 416baaa9-dc9f-4396-8d5f-8c081fb06d67
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
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.