CVE-2026-43315: Linux kernel · KVM: nSVM: Remove a user-triggerable WARN on nested_svm_load_cr3() succeeding
Affects Linux kernelSource GCVE Database
Not known to be exploited · CVSS 5.5 Medium · fixed in 6.8.0-1060.63~22.04.1 : update Linux kernel when convenient.
Data as of 26 Oct 2026, 14:05 UTC
- EPSS
- 0.1% chance of exploitation in 30 days – higher than 2% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in 6.8.0-1060.63~22.04.1, 6.8.0-1063.69~22.04.1, 6.8.0-1060.61~22.04.1 +24
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 8 May 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 26 Oct 2026.
What to do
Upgrade to a fixed release listed under Affected software.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
Ubuntu 26.04 LTSlinux-azure-fdepkg:deb/ubuntu/linux-azure-fde@7.0.0-1008.8?arch=source&distro=resoluteOther threats | Affected
| Fixed in– |
Ubuntu 25.10linuxpkg:deb/ubuntu/linux@6.17.0-40.40?arch=source&distro=questingOther threats | Affected
| Fixed in– |
Ubuntu 25.10linux-awspkg:deb/ubuntu/linux-aws@6.17.0-1019.19?arch=source&distro=questingOther threats | Affected
| Fixed in– |
Ubuntu 25.10linux-azurepkg:deb/ubuntu/linux-azure@6.17.0-1020.20?arch=source&distro=questingOther threats | Affected
| Fixed in– |
Ubuntu 25.10linux-azure-fdepkg:deb/ubuntu/linux-azure-fde@6.17.0-1017.17?arch=source&distro=questingOther threats | Affected
| Fixed in– |
Ubuntu 25.10linux-gcppkg:deb/ubuntu/linux-gcp@6.17.0-1020.22?arch=source&distro=questingOther 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 has been released to remove the user-triggerable WARN in the nested_svm_load_cr3() function. Users should apply the official Linux kernel updates that include this fix. The vendor advisory confirms the availability of this fix. No additional mitigation is required beyond applying the update.
Description
A vulnerability in the Linux kernel's KVM nested SVM implementation allowed a user-triggerable WARN message on nested_svm_load_cr3() calls. This WARN could be trivially triggered from userspace by modifying CPUID after loading CR3, causing unnecessary warnings without meaningful protection. The issue was resolved by removing the WARN to prevent spurious messages and avoid breaking userspace. The vulnerability affects certain Linux kernel versions and has a medium severity rating with no confidentiality or integrity impact but potential availability impact.
References
- ubuntu.com/security/CVE-2026-43315 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2026-43315 (opens in a new tab)
- git.kernel.org/linus/fc3ba56385d03501eb582e4b86691ba378e556f9 (opens in a new tab)
- git.kernel.org/stable/c/155ec243ef726f4bc49536fa0bfb565dc011ab17 (opens in a new tab)
- git.kernel.org/stable/c/580ea57840864d40e019bc13fd26afdc8d510a2f (opens in a new tab)
- git.kernel.org/stable/c/969e5e13ff5c18603f21d1f9f64ec9194e141ac0 (opens in a new tab)
- git.kernel.org/stable/c/ce904c8a5bbe697eae0f7e34b07095bd7a6dee19 (opens in a new tab)
- git.kernel.org/stable/c/deb8f6dfd31d94b18dbeeaa8c01fbec5fc70fd2b (opens in a new tab)
- git.kernel.org/stable/c/ebb2ab4f1c87d6b52776292cf7dc16aea48e95f8 (opens in a new tab)
- git.kernel.org/stable/c/fc3ba56385d03501eb582e4b86691ba378e556f9 (opens in a new tab)
- ubuntu.com/security/notices/USN-8492-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8492-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-8497-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8498-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8499-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8492-3 (opens in a new tab)
- ubuntu.com/security/notices/USN-8492-4 (opens in a new tab)
- ubuntu.com/security/notices/USN-8492-5 (opens in a new tab)
- ubuntu.com/security/notices/USN-8575-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8576-1 (opens in a new tab)