CVE-2026-23198: Linux kernel · KVM: Don't clobber irqfd routing type when deassigning irqfd
Affects Linux kernelSource GCVE Database
Not known to be exploited · CVSS 7.8 High · fixed in 5.15.0-1111.118~20.04.1 : patch Linux kernel soon.
Data as of 26 Oct 2026, 13:47 UTC
- EPSS
- 0.1% chance of exploitation in 30 days – higher than 3% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in 5.15.0-1111.118~20.04.1, 5.15.0-1116.125~20.04.1, 5.15.0-1111.121~20.04.1 +58
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:HExploitation evidence
Disclosed: evidence found.
CVE published 14 Feb 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 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– |
Ubuntu 25.10linux-oraclepkg:deb/ubuntu/linux-oracle@6.17.0-1018.18?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 included in linux-aws kernel versions 5.15.0-1111.118~20.04.1, 5.15.0-1116.125~20.04.1, 5.15.0-1111.121~20.04.1, and 5.15.0-185.195~20.04.1 or later. Users should update their Linux kernel packages to these or newer versions and reboot to apply the fixes. Due to an ABI change, recompilation and reinstallation of third-party kernel modules may be required. Follow vendor instructions for updating and rebuilding kernel modules. No alternative mitigations are specified.
Description
A vulnerability in the Linux kernel's KVM subsystem was resolved that involved improper handling of irqfd routing entries when deassigning irqfds. This flaw could break certain architecture-specific IRQ routing functions on x86 and arm64, potentially leading to system compromise. The issue was fixed by ensuring the irqfd's routing entry is not clobbered during deassignment and verifying irqfd activity before consuming routing information. This vulnerability affects linux-aws kernel versions prior to specified patched releases. A patch is available and should be applied to mitigate the risk.
References
- ubuntu.com/security/CVE-2026-23198 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2026-23198 (opens in a new tab)
- git.kernel.org/linus/b4d37cdb77a0015f51fee083598fa227cc07aaf1 (opens in a new tab)
- git.kernel.org/stable/c/2284bc168b148a17b5ca3b37b3d95c411f18a08d (opens in a new tab)
- git.kernel.org/stable/c/4385b2f2843549bfb932e0dcf76bf4b065543a3c (opens in a new tab)
- git.kernel.org/stable/c/6d14ba1e144e796b5fc81044f08cfba9024ca195 (opens in a new tab)
- git.kernel.org/stable/c/959a063e7f12524bc1871ad1f519787967bbcd45 (opens in a new tab)
- git.kernel.org/stable/c/b4d37cdb77a0015f51fee083598fa227cc07aaf1 (opens in a new tab)
- git.kernel.org/stable/c/b61f9b2fcf181451d0a319889478cc53c001123e (opens in a new tab)
- git.kernel.org/stable/c/ff48c9312d042bfbe826ca675e98acc6c623211c (opens in a new tab)
- ubuntu.com/security/notices/USN-8278-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8289-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8296-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8296-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-8289-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-8278-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-8393-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8440-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8493-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8499-1 (opens in a new tab)