CVE-2026-98464: Linux kernel · RISC-V: KVM: Synchronize hrtimer callback during teardown
Affects Linux kernelSource CVE Database V5
Not known to be exploited · CVSS 9.3 Critical · fixed in ea91f05a55b807ead3166546a2c75f4185ca645f : patch Linux kernel as a priority.
Data as of 26 Oct 2026, 12:55 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 ea91f05a55b807ead3166546a2c75f4185ca645f, e66aced74f0122380603c9910a71d77618b28f0e, aaad136d56d91252517272b68cd533e5714698d5 +3
CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:HExploitation evidence
Disclosed: evidence found.
CVE published 18 Oct 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 is available and has been applied in multiple upstream Linux kernel commits. Users should update to a Linux kernel version that includes the patches identified by the fixed commit hashes (e.g., ea91f05a55b807ead3166546a2c75f4185ca645f and others). No additional mitigation is required beyond applying the official kernel updates that synchronize hrtimer_cancel() with running callbacks to prevent use-after-free during vCPU teardown.
Description
CVE-2026-98464 is a critical vulnerability in the Linux kernel's RISC-V KVM implementation involving a race condition during hrtimer callback teardown. The flaw allows a use-after-free condition where a vCPU can be freed while a timer callback is still running, potentially leading to kernel memory corruption. This occurs when the timer is armed by a guest and the VM is destroyed concurrently, causing a race between timer callback execution and vCPU destruction. The issue has been fixed by ensuring hrtimer_cancel() synchronizes with any running callbacks before vCPU teardown.
References
- git.kernel.org/stable/c/9bdbae64ae0dab93041ebc57ec4e93def793fc2d (opens in a new tab)
- git.kernel.org/stable/c/2af03b606aadaaeb386658ef798c79bdcdef87c1 (opens in a new tab)
- git.kernel.org/stable/c/e66aced74f0122380603c9910a71d77618b28f0e (opens in a new tab)
- git.kernel.org/stable/c/ea91f05a55b807ead3166546a2c75f4185ca645f (opens in a new tab)
- git.kernel.org/stable/c/3cc6184bd5920c9685d87f4e260568feba08650d (opens in a new tab)
- git.kernel.org/stable/c/aaad136d56d91252517272b68cd533e5714698d5 (opens in a new tab)