CVE-2025-23145: Linux kernel · mptcp: fix NULL pointer in can_accept_new_subflow
Source GCVE Database
Not known to be exploited · CVSS 5.5 Medium.
Data as of 4 Nov 2026, 18:11 UTC
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:HExploitation evidence
Disclosed: evidence found.
CVE published 1 May 2025
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 4 Nov 2026.
What to do
AI-suggested
A fix has been implemented in the Linux kernel source code to address this issue. Users and administrators should apply the official kernel update that includes this patch to prevent kernel panics caused by this NULL pointer dereference. Since this is not a cloud service, manual patching is required. No other mitigation steps are indicated.
Description
A NULL pointer dereference vulnerability in the Linux kernel's MPTCP implementation was fixed. The issue occurred in the function mptcp_can_accept_new_subflow when subflow_req->msk was NULL due to concurrent processing of SYN-ACK packets, potentially causing kernel panic. The patch moves the subflow_req->msk assignment under a conditional to prevent this dereference.
References
- nvd.nist.gov/vuln/detail/CVE-2025-23145 (opens in a new tab)
- git.kernel.org/stable/c/443041deb5ef6a1289a99ed95015ec7442f141dc (opens in a new tab)
- git.kernel.org/stable/c/4b2649b9717678aeb097893cc49f59311a1ecab0 (opens in a new tab)
- git.kernel.org/stable/c/7f9ae060ed64aef8f174c5f1ea513825b1be9af1 (opens in a new tab)
- git.kernel.org/stable/c/855bf0aacd51fced11ea9aa0d5101ee0febaeadb (opens in a new tab)
- git.kernel.org/stable/c/8cf7fef1bb2ffea7792bcbf71ca00216cecc725d (opens in a new tab)
- git.kernel.org/stable/c/b3088bd2a6790c8efff139d86d7a9d0b1305977b (opens in a new tab)
- git.kernel.org/stable/c/dc81e41a307df523072186b241fa8244fecd7803 (opens in a new tab)
- git.kernel.org/stable/c/efd58a8dd9e7a709a90ee486a4247c923d27296f (opens in a new tab)
- lists.debian.org/debian-lts-announce/2025/05/msg00030.html (opens in a new tab)
- lists.debian.org/debian-lts-announce/2025/05/msg00045.html (opens in a new tab)