CVE-2025-39682

HIGH EPSS 7.6%
Published Sep 5, 20259mo ago · Modified Jun 17, 20261w ago
7.1 CVSS 3.1
High
Find Similar
Published Sep 5, 2025 9mo ago
Last Modified Jun 17, 2026 1w ago

Description

In 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 Details

Base Score
7.1
Exploitability
1.8
Impact
5.2
Vector string
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H
Attack Vector Local
Attack Complexity Low
Privileges Required Low
User Interaction None
Scope Unchanged
Confidentiality High
Integrity None
Availability High

Threat Intelligence

EPSS Exploit Probability
7.6% percentile
Exploit & Patch Status
No Known Exploit
Patch Available

Affected Products 7

VendorProductVersionRange
linuxlinux_kernel*≥6.0  –  <6.1.149
linuxlinux_kernel*≥6.2  –  <6.6.103
linuxlinux_kernel*≥6.7  –  <6.12.44
linuxlinux_kernel*≥6.13  –  <6.16.4
linuxlinux_kernel6.17any
linuxlinux_kernel6.17any
debiandebian_linux11.0any

References 7

  • cert-portal.siemens.com https://cert-portal.siemens.com/productcert/html/ssa-032379.html
  • git.kernel.org https://git.kernel.org/stable/c/2902c3ebcca52ca845c03182000e8d71d3a5196f
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/29c0ce3c8cdb6dc5d61139c937f34cb888a6f42e
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/3439c15ae91a517cf3c650ea15a8987699416ad9
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/62708b9452f8eb77513115b17c4f8d1a22ebf843
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/c09dd3773b5950e9cfb6c9b9a5f6e36d06c62677
    Patch
  • lists.debian.org https://lists.debian.org/debian-lts-announce/2025/10/msg00008.html
    Mailing ListThird Party Advisory

Remediation

  • git.kernel.org https://git.kernel.org/stable/c/2902c3ebcca52ca845c03182000e8d71d3a5196f
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/29c0ce3c8cdb6dc5d61139c937f34cb888a6f42e
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/3439c15ae91a517cf3c650ea15a8987699416ad9
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/62708b9452f8eb77513115b17c4f8d1a22ebf843
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/c09dd3773b5950e9cfb6c9b9a5f6e36d06c62677
    Patch