CVE-2026-52993
Linux Kernel double free
- Published24 Jun 2026
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 breakdown
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:HAffected products
Remediation
- 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
References
- 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://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
and 5 more references
Related CVEs
Recent high-severity vulnerabilities sharing a weakness type.
Frequently asked
Is CVE-2026-52993 being actively exploited?
CVE-2026-52993 is not in the CISA KEV catalog. Its EPSS exploit probability is 0.40%.
How severe is CVE-2026-52993?
CVE-2026-52993 has a CVSS 3.1 base score of 9.8, rated critical. EPSS estimates a 0.40% probability of exploitation.
Which products are affected by CVE-2026-52993?
Affected products include Linux Kernel.
How do I fix CVE-2026-52993?
Upgrade affected software to a fixed version, for example Linux Kernel 5.10.258 or later, then confirm no affected versions remain in your inventory.
How Secuno handles this
Secuno correlates vulnerabilities like CVE-2026-52993 against the real software inventory on every managed device, every day. Rather than a static severity, each match is scored in context: exploit availability, EPSS, the asset's exposure, and business criticality decide where it lands in the queue. If an affected version is present anywhere across your portfolio, it surfaces automatically with a prioritised remediation path.
Data from the NVD, CISA KEV catalog and FIRST EPSS. CVSS 3.1 base score shown where available.