Skip to main content
VulnerabilityPublished Updated

CVE-2026-52993: Linux kernel · tipc: fix double-free in tipc_buf_append()

Affects Linux kernelSource CVE Database V5

0

Not known to be exploited · CVSS 9.8 Critical · fixed in d3556656c6daebf8def751c7e71d11dd0a180d24 : patch Linux kernel as a priority.

Data as of 26 Oct 2026, 17:16 UTC

CVSS 3.1 base score
9.8Critical
How severe the flaw is on the 0–10 CVSS scale.
EPSS
0.4% chance of exploitation in 30 days – higher than 34% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
CISA SSVC
Exploitation
No evidence of active exploitation and no public proof of concept
Automatable
Attackers can reliably automate steps 1–4 of the kill chain
Technical impact
Total control over the software or total information disclosure

CISA SSVC assessment, 2026-10-16.

Patch
Available – fixed in d3556656c6daebf8def751c7e71d11dd0a180d24, d293ca716e7d5dffdaecaf6b9b2f857a33dc3d3a, a438975a6dcdbd70865978c021650d1485586f0b +5
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Exploitation evidence

  1. Disclosed: evidence found.

    CVE published 24 Jun 2026

  2. Detectable: no evidence on record.

    No public nuclei template indexed

  3. Weaponised: no evidence on record.

    No public exploit code indexed in Metasploit or Exploit-DB

  4. Exploited in the wild: no evidence on record.

    Not in CISA KEV and no source reports exploitation

  5. Observed by OffSeq Mirage: no evidence on record.

    No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.

What to do

Upgrade to a fixed release listed under Affected software.

Affected software

ProductAffectedFixed in
LinuxLinuxAffected
  • ≥ d618d09a68e4eed7a435beb2e355250f6f40664a, < d3556656c6daebf8def751c7e71d11dd0a180d24
Fixed in
  • d3556656c6daebf8def751c7e71d11dd0a180d24
LinuxLinuxAffected
  • ≥ d618d09a68e4eed7a435beb2e355250f6f40664a, < d293ca716e7d5dffdaecaf6b9b2f857a33dc3d3a
Fixed in
  • d293ca716e7d5dffdaecaf6b9b2f857a33dc3d3a
LinuxLinuxAffected
  • ≥ d618d09a68e4eed7a435beb2e355250f6f40664a, < a438975a6dcdbd70865978c021650d1485586f0b
Fixed in
  • a438975a6dcdbd70865978c021650d1485586f0b
LinuxLinuxAffected
  • ≥ d618d09a68e4eed7a435beb2e355250f6f40664a, < 29940fff14110ca48c5ccc168d121665b51bb778
Fixed in
  • 29940fff14110ca48c5ccc168d121665b51bb778
LinuxLinuxAffected
  • ≥ d618d09a68e4eed7a435beb2e355250f6f40664a, < 0274f24485fc38032d4093e463dc3ff5c7a667c9
Fixed in
  • 0274f24485fc38032d4093e463dc3ff5c7a667c9
LinuxLinuxAffected
  • ≥ d618d09a68e4eed7a435beb2e355250f6f40664a, < 4ee4deadaae7cb2e3d53af0fc889cf92a73413c0
Fixed in
  • 4ee4deadaae7cb2e3d53af0fc889cf92a73413c0

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.

References

Community reviews

Loading reviews…