CVE-2025-37957: Linux kernel · KVM: SVM: Forcibly leave SMM mode on SHUTDOWN interception
Affects Linux kernelSource GCVE Database
Not known to be exploited · CVSS 8.8 High · fixed in 6.8.0-1046.49~22.04.1 : patch Linux kernel soon.
Data as of 26 Oct 2026, 16:39 UTC
- EPSS
- 0.1% chance of exploitation in 30 days – higher than 8% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in 6.8.0-1046.49~22.04.1, 6.8.0-1051.57~22.04.1, 6.8.0-1046.53~22.04.1 +32
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:HExploitation evidence
Disclosed: evidence found.
CVE published 20 May 2025
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 26 Oct 2026.
What to do
Upgrade to a fixed release listed under Affected software.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
Ubuntu 25.10linux-azure-fdepkg:deb/ubuntu/linux-azure-fde?arch=source&distro=questingOther threats | Affected
| Fixed in– |
Ubuntu 24.04 LTSlinuxpkg:deb/ubuntu/linux?arch=source&distro=nobleOther threats | Affected
| Fixed in
|
Ubuntu 24.04 LTSlinux-awspkg:deb/ubuntu/linux-aws?arch=source&distro=nobleOther threats | Affected
| Fixed in
|
Ubuntu 24.04 LTSlinux-aws-6.14pkg:deb/ubuntu/linux-aws-6.14?arch=source&distro=nobleOther threats | Affected
| Fixed in
|
Ubuntu 24.04 LTSlinux-azurepkg:deb/ubuntu/linux-azure?arch=source&distro=nobleOther threats | Affected
| Fixed in
|
Ubuntu 24.04 LTSlinux-azure-6.11pkg:deb/ubuntu/linux-azure-6.11?arch=source&distro=nobleOther threats | Affected
| Fixed in– |
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
AI-suggested
A patch is available and should be applied. The vendor advisory from Ubuntu confirms that this and several other Linux kernel vulnerabilities have been fixed in updated kernel packages. Users should update to the fixed kernel versions and reboot to apply changes. Due to ABI changes, recompilation and reinstallation of third-party kernel modules may be necessary. No additional mitigation is required beyond applying the official kernel updates.
Description
A vulnerability in the Linux kernel's KVM subsystem for x86 SVM was resolved that involved improper handling of System Management Mode (SMM) during SHUTDOWN interception. Previously, a commit addressed use-after-free issues in nested mode but did not handle the analogous SMM case, causing a kernel warning when KVM forces a vCPU INIT after SHUTDOWN interception while the vCPU is in SMM. This could lead to instability or crashes under specific conditions involving invalid instructions and triple faults. The issue was discovered using Syzkaller and fixed by forcing the vCPU out of SMM on SHUTDOWN to avoid the warning and undefined behavior.
References
- ubuntu.com/security/CVE-2025-37957 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2025-37957 (opens in a new tab)
- git.kernel.org/linus/a2620f8932fa9fdabc3d78ed6efb004ca409019f (opens in a new tab)
- git.kernel.org/stable/c/a2620f8932fa9fdabc3d78ed6efb004ca409019f (opens in a new tab)
- git.kernel.org/stable/c/d362b21fefcef7eda8f1cd78a5925735d2b3287c (opens in a new tab)
- git.kernel.org/stable/c/e9b28bc65fd3a56755ba503258024608292b4ab1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7699-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7699-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-7721-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8028-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8028-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-8031-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8028-3 (opens in a new tab)
- ubuntu.com/security/notices/USN-8028-4 (opens in a new tab)
- ubuntu.com/security/notices/USN-8028-5 (opens in a new tab)
- ubuntu.com/security/notices/USN-8031-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-8028-6 (opens in a new tab)
- ubuntu.com/security/notices/USN-8031-3 (opens in a new tab)
- ubuntu.com/security/notices/USN-8052-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8028-7 (opens in a new tab)