CVE-2025-39682
HighIn the Linux kernel, the following vulnerability has been resolved: tls: fix handling of zero-length records on the rx_list Each recvmsg() call must process either - only contiguous DATA records (any number of them) - one non-DATA record If the next record has different type than what has already been processed we break out of the main processing loop. If the record has already been decrypted (which may be the case for TLS 1.3 where we don't know type until decryption) we queue the pending record to the rx_list. Next recvmsg() will pick it up from there. Queuing the skb to rx_list after zero-copy decrypt is not possible, since in that case we decrypted directly to the user space buffer, and we don't have an skb to queue (darg.skb points to the ciphertext skb for access to metadata like length). Only data records are allowed zero-copy, and we break the processing loop after each non-data record. So we should never zero-copy and then find out that the record type has changed. The corner case we missed is when the initial record comes from rx_list, and it's zero length.
CVSS 3.1 score
7.1
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H
Affected versions
Linux kernel versions
6.0
and later are affected. Fixed in
6.1.149,
6.6.103,
6.12.44,
6.16.4,
6.17
and their respective stable series.
References
The following references provide additional information about CVE-2025-39682 including vendor advisories, patch commits, exploit details, and third-party analysis. Links are sourced from the NIST NVD database.
-
Mailing List Third Party Advisory
-
-
PatchKernel patch commithttps://git.kernel.org/stable/c/2902c3ebcca52ca845c03182000e8d71d3a5196f
-
PatchKernel patch commithttps://git.kernel.org/stable/c/29c0ce3c8cdb6dc5d61139c937f34cb888a6f42e
-
PatchKernel patch commithttps://git.kernel.org/stable/c/3439c15ae91a517cf3c650ea15a8987699416ad9
Frequently asked questions
-
What is CVE-2025-39682?
CVE-2025-39682 is a High severity Linux kernel vulnerability with a CVSS score of 7.1 out of 10 . It affects Linux kernel versions from 6.0 onward and has been patched in 6.1.149, 6.6.103, 6.12.44 and others. CVE-2025-39682 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.
-
What is the CVSS score for CVE-2025-39682?
CVE-2025-39682 has a CVSS score of 7.1 out of 10, rated High severity (CVSS 3.1). The vector string is
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H. -
Is there a patch available for CVE-2025-39682?
Yes — CVE-2025-39682 has been patched. Fixed versions include 6.1.149, 6.6.103, 6.12.44 and others. If you are running Linux kernel 6.0 or later up to the fix versions, apply the relevant patch for your kernel branch.
-
Is CVE-2025-39682 actively exploited?
No — CVE-2025-39682 has not been confirmed as actively exploited. It is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.