Review reviewHigh

CVE-2025-40133

Linux

In the Linux kernel, the following vulnerability has been resolved: mptcp: Use __sk_dst_get() and dst_dev_rcu() in mptcp_active_enable(). mptcp_active_enable() is called from subflow_finish_connect(), which is icsk->icsk_af_ops->sk_rx_dst_set() and it's not always under RCU. Using sk_dst_get(sk)->dev could trigger UAF. Let's use __sk_dst_get() and dst_dev_rcu().

CVSS
8.1
EPSS
0.47%
38.1% percentile
CISA KEV
Not listed
Published
2025.11.12
PRIORITY ASSESSMENT

Review review

The CVSS severity warrants an early asset and exposure review.

Known exploitationNot established by KEV
Exploit probability0.47%
Technical severityCVSS 8.1

Vulnerability overview

In the Linux kernel, the following vulnerability has been resolved: mptcp: Use __sk_dst_get() and dst_dev_rcu() in mptcp_active_enable(). mptcp_active_enable() is called from subflow_finish_connect(), which is icsk->icsk_af_ops->sk_rx_dst_set() and it's not always under RCU. Using sk_dst_get(sk)->dev could trigger UAF. Let's use __sk_dst_get() and dst_dev_rcu().

Affected product and versions

Product
Linux
Affected versions
>= 27069e7cb3d1cea9377069266acf19b9cc5ad0ae < ad16235c9d3ef7ec17c109ff39b7504f49d17072, >= 27069e7cb3d1cea9377069266acf19b9cc5ad0ae < cc976ec9e38bb79409de3261ba1dbb6868e2a53e, >= 27069e7cb3d1cea9377069266acf19b9cc5ad0ae < 893c49a78d9f85e4b8081b908fb7c407d018106a, >= 6.12
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:H/PR:N/UI:N/S:U/C:H/I:H/A:H
CWE
Not available