VulnerabilityPublished 18 Oct 2026

CVE-2026-98712: Linux kernel · KVM: arm64: vgic: Take a refcount on IRQs referenced by last_lr_irq

Source GCVE Database

Authoritative record:CVE-2026-98712· Medium

Not known to be exploited · fixed in 19bc5d79ece613f242b5ec03921a3b465321bfed : update Linux kernel when convenient.

Data as of 26 Oct 2026, 17:16 UTC

Severity

Medium

Rated by Threat Radar · CVSS not yet scored by NVD

EPSS: 0.1% chance of exploitation in 30 days – higher than 4% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch: Available – fixed in 19bc5d79ece613f242b5ec03921a3b465321bfed, 8b25393d16a5ca8df907bd7ee1ff2e9d85678b3c, 6.20

Exploitation 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.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponised: Public exploit code exists in Metasploit or Exploit-DB, or CISA SSVC or the CVSS exploit maturity reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

ghsa-fqwg-6qxx-rx2q

What to do

Upgrade Linux to 19bc5d79ece613f242b5ec03921a3b465321bfed, 8b25393d16a5ca8df907bd7ee1ff2e9d85678b3c or 6.20; the Debian debian/linux package to 6.20.

Affected software

Product	Affected	Fixed in
LinuxLinux	Affected >=6.19.9 <6.20	Fixed in 19bc5d79ece613f242b5ec03921a3b465321bfed 8b25393d16a5ca8df907bd7ee1ff2e9d85678b3c 6.20
LinuxLinux	Affected =7.0	Fixed in–
Debiandebian/linux`pkg:deb/debian/linux`Other threats	Affected >=6.19.9 <6.20 =7.0	Fixed in 6.20

Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.

AI-suggested

An official fix has been applied to the Linux kernel to address this issue by properly managing reference counts on interrupts referenced by last_lr_irq. Users should update to a Linux kernel version that includes this fix. Since this is a kernel-level vulnerability, applying the updated kernel version is the recommended remediation.

Description

A vulnerability in the Linux kernel's KVM arm64 virtual generic interrupt controller (vgic) component has been resolved. The issue involved improper reference counting on interrupts referenced by last_lr_irq, which could vanish if a concurrently unmapped LPI (Locality-specific Peripheral Interrupt) occurred. The fix involves incrementing the reference count when populating last_lr_irq and decrementing it during LPI reclamation.

Impact

The vulnerability could cause instability or incorrect behavior in the KVM arm64 virtual interrupt controller due to referencing interrupts that might have been concurrently unmapped. This could potentially lead to kernel crashes or undefined behavior in virtualized environments using KVM on arm64 architectures. No known exploits in the wild have been reported.

Summary

The vulnerability in the Linux kernel affects the KVM arm64 vgic implementation. Specifically, referencing the last interrupt inserted in a List Register (LR) was fragile because the interrupt could disappear if an LPI was concurrently unmapped. This could lead to use-after-free or similar issues related to interrupt handling. The resolution was to increase the reference count on the interrupt when setting last_lr_irq and to drop the reference count when LPIs are reclaimed in vgic_prune_ap_list().

References

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