CVE-2026-63806: KVM: Replace guest-triggerable BUG_ON() in ioeventfd datamatch with get_unaligned()

highCVSS 7.3CVE-2026-63806

CSIRTS triage

vendor: Linux product: KVMOther

What: This vulnerability replaces a guest-triggerable BUG_ON() in ioeventfd datamatch with get_unaligned().
Who is affected: Deployments using KVM with the affected ioeventfd functionality.
Urgency: Remediation is advised to avoid potential system instability, though no exploitation has been reported.
Action: Update the KVM code to replace the BUG_ON() with get_unaligned().

AI-assisted analysis generated from the source advisory — verify against the original.

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Details

Source: Microsoft Security Response Center (INTL · vendor-psirt · site)
Severity: high — CVSS 7.3
Published: 2026-07-14
Exploitation: Not in CISA KEV at last sync

Original advisory: https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-63806

Exploitation outlook

EPSS (FIRST.org) estimates each CVE’s probability of exploitation in the next 30 days — here is the CSIRTS.com read on those numbers.

Low exploitation riskCVE-2026-638060.15% 30-day exploitation probability — currently an unlikely target, but scores change as exploit code circulates. Riskier than 4% of all scored CVEs.

Referenced CVEs

CVE	CSIRTS overview	External
CVE-2026-63806	coverage & exploitation status	NVD · CVE.org

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