PT-2025-40646 · Linux+3 · Linux Kernel+3

Published

2025-09-14

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Updated

2026-05-07

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CVE-2025-39950

CVSS v3.1

5.5

Medium

VectorAV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Name of the Vulnerable Software and Affected Versions Linux kernel (affected versions not specified)
Description A flaw exists in the Linux kernel related to a NULL pointer dereference within the tcp ao finish connect() function when TCP-AO is used in conjunction with TCP REPAIR. This issue can occur during a connect() system call on a socket with a TCP-AO key added and TCP REPAIR enabled. The function attempts to dereference a potentially NULL skb pointer without prior validation, leading to a crash. The vulnerability is triggered when the skb is NULL and the code attempts to access tcp hdr(skb)->seq. A proof-of-concept demonstrates the issue by setting up a socket with TCP-AO and TCP REPAIR enabled, then initiating a connection.
Recommendations At the moment, there is no information about a newer version that contains a fix for this vulnerability.

Exploit

NULL Pointer Dereference

Weakness Enumeration

CWE-476

Related Identifiers

BDU:2026-02685
CVE-2025-39950
OPENSUSE-SU-2025:20091-1
SUSE-SU-2025:21080-1
SUSE-SU-2025:21147-1
SUSE-SU-2025:21180-1
USN-8095-1
USN-8095-2
USN-8095-3
USN-8095-4
USN-8095-5
USN-8100-1
USN-8125-1
USN-8126-1
USN-8165-1
USN-8261-1

Affected Products

Linuxmint
Linux Kernel
Suse
Ubuntu