CVE-2025-38566

High

In the Linux kernel, the following vulnerability has been resolved: sunrpc: fix handling of server side tls alerts Scott Mayhew discovered a security exploit in NFS over TLS in tls_alert_recv() due to its assumption it can read data from the msg iterator's kvec.. kTLS implementation splits TLS non-data record payload between the control message buffer (which includes the type such as TLS aler or TLS cipher change) and the rest of the payload (say TLS alert's level/description) which goes into the msg payload buffer. This patch proposes to rework how control messages are setup and used by sock_recvmsg(). If no control message structure is setup, kTLS layer will read and process TLS data record types. As soon as it encounters a TLS control message, it would return an error. At that point, NFS can setup a kvec backed msg buffer and read in the control message such as a TLS alert. Msg iterator can advance the kvec pointer as a part of the copy process thus we need to revert the iterator before calling into the tls_alert_recv.

Package Linux Kernel
Published 2025-08-19
Last modified 2025-11-26
CVSS version 3.1
Patch available
Yes

CVSS 3.1 score

7.5

out of 10
High
Attack Vector
Network
Attack Complexity
Low
Privileges Required
None
User Interaction
None
Scope
Unchanged
Confidentiality
Low
Integrity
None
Availability
High
Vector string
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Weakness type

CWE-754

CVE-2025-38566 is classified as CWE-754

See CWE-754 on MITRE CWE for full details on this weakness type.

Affected versions

Linux kernel versions 6.4 and later are affected. Fixed in 6.6.102, 6.12.42, 6.15.10, 6.16.1, 6.17 and their respective stable series.

Affected from
≥ 6.4
Fixed in
✓ 6.6.102 6.6.x ✓ 6.12.42 6.12.x ✓ 6.15.10 6.15.x ✓ 6.16.1 6.16.x ✓ 6.17

References

The following references provide additional information about CVE-2025-38566 including vendor advisories, patch commits, exploit details, and third-party analysis. Links are sourced from the NIST NVD database.

5 patch commits total View all on NVD

Frequently asked questions

  • What is CVE-2025-38566?

    CVE-2025-38566 is a High severity Linux kernel vulnerability with a CVSS score of 7.5 out of 10 . It affects Linux kernel versions from 6.4 onward and has been patched in 6.6.102, 6.12.42, 6.15.10 and others. CVE-2025-38566 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

  • What is the CVSS score for CVE-2025-38566?

    CVE-2025-38566 has a CVSS score of 7.5 out of 10, rated High severity (CVSS 3.1). The vector string is CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H .

  • Is there a patch available for CVE-2025-38566?

    Yes — CVE-2025-38566 has been patched. Fixed versions include 6.6.102, 6.12.42, 6.15.10 and others. If you are running Linux kernel 6.4 or later up to the fix versions, apply the relevant patch for your kernel branch.

  • Is CVE-2025-38566 actively exploited?

    No — CVE-2025-38566 has not been confirmed as actively exploited. It is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.

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