CVE-2026-23198: Linux kernel · Use After Free
Affects Linux kernelSource CVE Database V5
Not known to be exploited · CVSS 7.8 High · fixed in ff48c9312d042bfbe826ca675e98acc6c623211c : patch Linux kernel soon.
Data as of 26 Oct 2026, 17:30 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.
- CISA SSVC
- Exploitation
- No evidence of active exploitation and no public proof of concept
- Automatable
- Attackers cannot reliably automate steps 1–4 of the kill chain
- Technical impact
- Total control over the software or total information disclosure
CISA SSVC assessment, 2026-06-16.
- Patch
- Available – fixed in ff48c9312d042bfbe826ca675e98acc6c623211c, b61f9b2fcf181451d0a319889478cc53c001123e, b4d37cdb77a0015f51fee083598fa227cc07aaf1 +4
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 |
|---|---|---|
| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in
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AI-suggested
A fix for this vulnerability is available and has been applied in specific Linux kernel commits. Users and administrators should update their Linux kernel to versions including these fixes to remediate the issue. No additional mitigation steps are indicated beyond applying the official patches.
Description
CVE-2026-23198 is a high-severity vulnerability in the Linux kernel's KVM subsystem where improper handling of irqfd routing entries during deassignment can lead to use-after-free conditions and kernel crashes. The flaw involves clobbering irqfd routing types, which breaks certain architecture-specific functions and can cause NULL pointer dereferences or list corruption, especially on AMD platforms. This issue has been fixed in specific Linux kernel commits.
References
- git.kernel.org/stable/c/959a063e7f12524bc1871ad1f519787967bbcd45 (opens in a new tab)
- git.kernel.org/stable/c/2284bc168b148a17b5ca3b37b3d95c411f18a08d (opens in a new tab)
- git.kernel.org/stable/c/6d14ba1e144e796b5fc81044f08cfba9024ca195 (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)
- git.kernel.org/stable/c/4385b2f2843549bfb932e0dcf76bf4b065543a3c (opens in a new tab)
- git.kernel.org/stable/c/b4d37cdb77a0015f51fee083598fa227cc07aaf1 (opens in a new tab)