VulnerabilityPublished 18 Oct 2026

CVE-2026-98469: Linux kernel · KVM: arm64: Fix AArch32 DBGBXVR<n> handling

Source GCVE Database

Authoritative record:CVE-2026-98469· High 7.1

Not known to be exploited · CVSS 7.1 High · fixed in af6813d16ace2765011ca1c567be86ade1d1ee8e : patch Linux kernel soon.

Data as of 26 Oct 2026, 14:05 UTC

CVSS 3.1 base score

7.1High

How severe the flaw is on the 0–10 CVSS scale.

EPSS: 0.1% chance of exploitation in 30 days – higher than 6% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch: Available – fixed in af6813d16ace2765011ca1c567be86ade1d1ee8e, 8530a05b304d312fe7dfbc5df7d3e87cc31b256a, 6b1bca1b1ab77f60a62087337bfe6e2f0efb9e6d

CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H

Attack Vector: Local
Attack Complexity: Low
Privileges Required: None
User Interaction: None
Scope: Changed
Confidentiality: None
Integrity: None
Availability: High

Bold values are the worst case: easiest to exploit or largest impact.

Attack Vector: Local: The vulnerable component is not bound to the network stack and the attacker’s path is via read/write/execute capabilities. Either: the attacker exploits the vulnerability by accessing the target system locally (e.g., keyboard, console), or remotely (e.g., SSH); or the attacker relies on User Interaction by another person to perform actions required to exploit the vulnerability (e.g., tricking a legitimate user into opening a malicious document).
Attack Complexity: Low: Specialized access conditions or extenuating circumstances do not exist. An attacker can expect repeatable success against the vulnerable component.
Privileges Required: None: The attacker is unauthorized prior to attack, and therefore does not require any access to settings or files to carry out an attack.
User Interaction: None: The vulnerable system can be exploited without any interaction from any user.
Scope: Changed: An exploited vulnerability can affect resources beyond the security scope managed by the security authority of the vulnerable component. In this case, the vulnerable component and the impacted component are different and managed by different security authorities.
Confidentiality: None: There is no loss of confidentiality within the impacted component.
Integrity: None: There is no loss of integrity within the impacted component.
Availability: High: There is total loss of availability, resulting in the attacker being able to fully deny access to resources in the impacted component; this loss is either sustained (while the attacker continues to deliver the attack) or persistent (the condition persists even after the attack has completed). Alternatively, the attacker has the ability to deny some availability, but the loss of availability presents a direct, serious consequence to the impacted component (e.g., the attacker cannot disrupt existing connections, but can prevent new connections; the attacker can repeatedly exploit a vulnerability that, in each instance of a successful attack, leaks a only small amount of memory, but after repeated exploitation causes a service to become completely unavailable).

Definitions: FIRST CVSS v3.1 specification.

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-vcw8-qqhm-h682

What to do

Upgrade Linux kernel to af6813d16ace2765011ca1c567be86ade1d1ee8e, 8530a05b304d312fe7dfbc5df7d3e87cc31b256a or 6b1bca1b1ab77f60a62087337bfe6e2f0efb9e6d.

Affected software

Product	Affected	Fixed in
LinuxLinux	Affected ≥ 3ce9f3357e9e099f02feaa002769eb99ef1138cd, < af6813d16ace2765011ca1c567be86ade1d1ee8e	Fixed in af6813d16ace2765011ca1c567be86ade1d1ee8e
LinuxLinux	Affected ≥ 3ce9f3357e9e099f02feaa002769eb99ef1138cd, < 8530a05b304d312fe7dfbc5df7d3e87cc31b256a	Fixed in 8530a05b304d312fe7dfbc5df7d3e87cc31b256a
LinuxLinux	Affected ≥ 3ce9f3357e9e099f02feaa002769eb99ef1138cd, < 6b1bca1b1ab77f60a62087337bfe6e2f0efb9e6d	Fixed in 6b1bca1b1ab77f60a62087337bfe6e2f0efb9e6d
LinuxLinux	Affected =6.14	Fixed in–

AI-suggested

A fix has been applied in the Linux kernel to correctly handle the DBGBXVR<n> register access in KVM arm64. Users should update to the fixed kernel version once available.

Description

A vulnerability in the Linux kernel's KVM module for arm64 architecture involving incorrect handling of the AArch32 DBGBXVR<n> register has been resolved. The issue was caused by a change in breakpoint and watchpoint register accessors that led to improper handling of Op2 values, causing the virtual machine to hit a fatal error and terminate. The fix restores correct mapping of Op2 1 to the appropriate debug register, preventing VM crashes.

Impact

An AArch32 guest accessing the DBGBXVR<n> register in the affected KVM arm64 implementation would trigger a kernel bug check (KVM_BUG_ON()), causing the virtual machine to be terminated unexpectedly. This results in denial of service for the affected VM.

Summary

The Linux kernel's KVM arm64 module had a vulnerability in handling the AArch32 DBGBXVR<n> register due to a consolidation of breakpoint and watchpoint register accessors. The DBGBXVR<n> register was switched from trap_bvr() to trap_dbg_wb_reg(), which only handled Op2 values 4 through 7. Since DBGBXVR<n> uses Op2 value 1, this caused a KVM_BUG_ON() failure, marking the virtual machine as dead. The fix maps Op2 1 to dbg_bvr[] alongside Op2 4, restoring the previous behavior and preventing VM crashes.

References

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