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VulnerabilityPublished Updated

CVE-2025-68775: Linux kernel · net/handshake: duplicate handshake cancellations leak socket

Source GCVE Database

0
Authoritative record:CVE-2025-68775· Critical 9.8

Not known to be exploited · CVSS 9.8 Critical · fixed in e1641177e7fb48a0a5a06658d4aab51da6656659 : patch Linux kernel as a priority.

Data as of 26 Oct 2026, 14:05 UTC

CVSS 3.1 base score
9.8Critical
How severe the flaw is on the 0–10 CVSS scale.
EPSS
0.5% chance of exploitation in 30 days – higher than 45% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch
Available – fixed in e1641177e7fb48a0a5a06658d4aab51da6656659, 15564bd67e2975002f2a8e9defee33e321d3183f, 011ae80c49d9bfa5b4336f8bd387cd25c7593663 +1
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 13 Jan 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 Linux kernel to e1641177e7fb48a0a5a06658d4aab51da6656659, 15564bd67e2975002f2a8e9defee33e321d3183f, 011ae80c49d9bfa5b4336f8bd387cd25c7593663 or 3c330f1dee3cd92b57e19b9d21dc8ce5970b09be.

Affected software

ProductAffectedFixed in
LinuxLinuxAffected
  • ≥ 3b3009ea8abb713b022d94fba95ec270cf6e7eae, < e1641177e7fb48a0a5a06658d4aab51da6656659
Fixed in
  • e1641177e7fb48a0a5a06658d4aab51da6656659
LinuxLinuxAffected
  • ≥ 3b3009ea8abb713b022d94fba95ec270cf6e7eae, < 15564bd67e2975002f2a8e9defee33e321d3183f
Fixed in
  • 15564bd67e2975002f2a8e9defee33e321d3183f
LinuxLinuxAffected
  • ≥ 3b3009ea8abb713b022d94fba95ec270cf6e7eae, < 011ae80c49d9bfa5b4336f8bd387cd25c7593663
Fixed in
  • 011ae80c49d9bfa5b4336f8bd387cd25c7593663
LinuxLinuxAffected
  • ≥ 3b3009ea8abb713b022d94fba95ec270cf6e7eae, < 3c330f1dee3cd92b57e19b9d21dc8ce5970b09be
Fixed in
  • 3c330f1dee3cd92b57e19b9d21dc8ce5970b09be
LinuxLinuxAffected
  • =6.4
Fixed in–

AI-suggested

The vulnerability description states it has been resolved by adding a test_and_set_bit for the HANDSHAKE_F_REQ_COMPLETED flag to detect duplicate cancellations. Security teams should monitor for official Linux kernel updates addressing CVE-2025-68775 and apply them promptly once available.

Description

A critical vulnerability in the Linux kernel's network handshake code allows duplicate handshake cancellations to leak socket references, leading to a reference count underflow. This occurs when a handshake request is cancelled multiple times but not properly marked as completed, causing improper socket reference handling. The issue can arise in scenarios such as SUNRPC client-server TLS handshake timeouts. The vulnerability has been resolved by adding a mechanism to detect and handle duplicate cancellations correctly.

References

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