Review reviewCritical

CVE-2026-63978

Linux

In the Linux kernel, the following vulnerability has been resolved: net/handshake: Drain pending requests at net namespace exit The arguments to list_splice_init() in handshake_net_exit() are reversed. The call moves the local empty "requests" list onto hn->hn_requests, leaving the local list empty, so the subsequent drain loop runs zero iterations. Pending handshake requests that had not yet been accepted are not torn down when the net namespace is destroyed; each one keeps a reference on a socket file and on the handshake_req allocation. Pass the source and destination in the documented o...

CVSS
9.8
EPSS
-
- percentile
CISA KEV
Not listed
Published
2026.07.20
PRIORITY ASSESSMENT

Review review

The CVSS severity warrants an early asset and exposure review.

Known exploitationNot established by KEV
Exploit probability-
Technical severityCVSS 9.8

Vulnerability overview

In the Linux kernel, the following vulnerability has been resolved: net/handshake: Drain pending requests at net namespace exit The arguments to list_splice_init() in handshake_net_exit() are reversed. The call moves the local empty "requests" list onto hn->hn_requests, leaving the local list empty, so the subsequent drain loop runs zero iterations. Pending handshake requests that had not yet been accepted are not torn down when the net namespace is destroyed; each one keeps a reference on a socket file and on the handshake_req allocation. Pass the source and destination in the documented o...

Affected product and versions

Product
Linux
Affected versions
>= 3b3009ea8abb713b022d94fba95ec270cf6e7eae < 9ec20c9a5a04f2c3f1cf65d21f886d7aaa6189cd, >= 3b3009ea8abb713b022d94fba95ec270cf6e7eae < 8c35539db0ab0bfa1ea44efab00b053261a69469, >= 3b3009ea8abb713b022d94fba95ec270cf6e7eae < ea5fe6a73ca57e5150b8a38b341aef2636eb72f0, >= 6.4
Fixed versions
No verified fixed-version field is available yet

Recommended response sequence

Confirm exposure before applying a vendor-supported change.

Full remediation guide
  1. 1
    Identify

    Confirm that Linux and an affected version are present.

  2. 2
    Prioritize

    Combine exploitation signals with asset exposure and business criticality.

  3. 3
    Remediate

    Follow the vendor advisory or supported update path and preserve rollback options.

  4. 4
    Verify

    Recheck the version, service health, access paths, and relevant logs.

Technical data

CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
CWE
Not available