Security update for the Linux Kernel RT (Live Patch 1 for SUSE Linux Enterprise 16)
Affects SUSESource GCVE Database
Not known to be exploited · fixed in 6.17.0-1011.11 : patch SUSE soon.
Data as of 26 Oct 2026, 07:57 UTC
Rated by Threat Radar · No CVSS score from NVD or the CNA
- EPSS
- 0.5% chance of exploitation in 30 days – higher than 47% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in 6.17.0-1011.11, 6.17.0-1008.8~24.04.1, 6.17.0-1008.8 +1
Exploitation evidence
Disclosed: evidence found.
CVE published 2 Mar 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: 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 2026-10-26.
What to do
Upgrade SUSE to 6.17.0-1011.11, 6.17.0-1008.8~24.04.1, 6.17.0-1008.8 or 6.17.0-1007.7~24.04.1.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| SUSE Product Security Team SUSE | Affected
| Fixed in
|
AI-suggested
An official patch is available and should be applied promptly. The fix removes the unsafe call to reqsk_fastopen_remove() in tcp_conn_request(), preventing the reference count underflow and double-free. Users should update their Linux kernel to version 6.17.0-1007.7 or later for SUSE Linux Enterprise 16 and related distributions. After updating, a system reboot is required to apply the kernel changes. No additional mitigation steps are indicated by the vendor advisory.
Description
A high-severity vulnerability in the Linux kernel's TCP stack was resolved by removing a problematic call to reqsk_fastopen_remove() in tcp_conn_request(). The flaw caused a reference count underflow and double-free of a request socket (reqsk) when a listener socket was closed during TCP Fast Open (TFO) processing. This could lead to kernel instability or crashes. The issue was reported by syzbot and affects multiple SUSE Linux Enterprise 16 kernel live patch versions prior to 6.17.0-1007.7 and related builds. A patch is available and should be applied to mitigate the risk.
References
- nvd.nist.gov/vuln/detail/CVE-2025-40186 (opens in a new tab)
- git.kernel.org/stable/c/2e7cbbbe3d61c63606994b7ff73c72537afe2e1c (opens in a new tab)
- git.kernel.org/stable/c/422c1c173c39bbbae1e0eaaf8aefe40b2596233b (opens in a new tab)
- git.kernel.org/stable/c/643a94b0cf767325e953591c212be2eb826b9d7f (opens in a new tab)
- git.kernel.org/stable/c/64dc47a13aa3d9daf7cec29b44dca8e22a6aea15 (opens in a new tab)
- git.kernel.org/stable/c/c11ace909e873118295e9eb22dc8c58b0b50eb32 (opens in a new tab)
- git.kernel.org/stable/c/e359b742eac1eac75cff4e38ee2e8cea492acd9b (opens in a new tab)
- git.kernel.org/stable/c/eb85ad5f23268d64b037bfb545cbcba3752f90c7 (opens in a new tab)
- git.kernel.org/stable/c/ff6a8883f96a5bc74241ce5b3d431a6dcfa2124d (opens in a new tab)
- ubuntu.com/security/CVE-2025-40186 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2025-40186 (opens in a new tab)
- git.kernel.org/linus/2e7cbbbe3d61c63606994b7ff73c72537afe2e1c (opens in a new tab)
- ubuntu.com/security/notices/USN-8029-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8030-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8029-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-8048-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8029-3 (opens in a new tab)
- suse.com/support/security/rating/ (opens in a new tab)
- ftp.suse.com/pub/projects/security/csaf/suse-su-2026_20558-1.json (opens in a new tab)
- suse.com/support/update/announcement/2026/suse-su-202620558-1/ (opens in a new tab)
- lists.suse.com/pipermail/sle-security-updates/2026-March/024587.html (opens in a new tab)
- bugzilla.suse.com/1253439 (opens in a new tab)
- suse.com/security/cve/CVE-2025-40186/ (opens in a new tab)