CVE-2026-52993
Medium
Elevated severity or exploit probability.
CVSS base
9.8
CRITICAL
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
EPSS — probability of exploitation (30 days)
0.4%
30.6th percentile
CISA KEV
Not listed
Weakness / dates
CWE-763
Published 2026-06-24 · modified 2026-08-03
CVSS breakdown
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
| Attack Vector | N | Network |
| Attack Complexity | L | Low |
| Privileges Required | N | None |
| User Interaction | N | None |
| Scope | U | Unchanged |
| Confidentiality | H | High |
| Integrity | H | High |
| Availability | H | High |
Timeline
- 2026-06-24 — Published (NVD)
- 2026-08-03 — Last modified (NVD)
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.
Affected
References
- https://git.kernel.org/stable/c/0274f24485fc38032d4093e463dc3ff5c7a667c9
- https://git.kernel.org/stable/c/1d5e589055880fae229e229e1929e087dbe08cf3
- https://git.kernel.org/stable/c/29940fff14110ca48c5ccc168d121665b51bb778
- https://git.kernel.org/stable/c/4d104882bc815d4ec666ace9155f5f52715879a6
- https://git.kernel.org/stable/c/4ee4deadaae7cb2e3d53af0fc889cf92a73413c0
- https://git.kernel.org/stable/c/a438975a6dcdbd70865978c021650d1485586f0b
- https://git.kernel.org/stable/c/d293ca716e7d5dffdaecaf6b9b2f857a33dc3d3a
- https://git.kernel.org/stable/c/d3556656c6daebf8def751c7e71d11dd0a180d24
- 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-2026-52993
- https://bugzilla.redhat.com/show_bug.cgi?id=2492437
- https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-52993.json