CVE-2026-46076

CVE-2026-46076 is a high-severity vulnerability in Linux Linux Kernel with a CVSS 3.x base score of 7.9. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low.

Key facts

Description

In the Linux kernel, the following vulnerability has been resolved: KVM: nSVM: Raise #UD if unhandled VMMCALL isn't intercepted by L1 Explicitly synthesize a #UD for VMMCALL if L2 is active, L1 does NOT want to intercept VMMCALL, nested_svm_l2_tlb_flush_enabled() is true, and the hypercall is something other than one of the supported Hyper-V hypercalls. When all of the above conditions are met, KVM will intercept VMMCALL but never forward it to L1, i.e. will let L2 make hypercalls as if it were L1. The TLFS says a whole lot of nothing about this scenario, so go with the architectural behavior, which says that VMMCALL #UDs if it's not intercepted. Opportunistically do a 2-for-1 stub trade by stub-ifying the new API instead of the helpers it uses. The last remaining "single" stub will soon be dropped as well. [sean: rewrite changelog and comment, tag for stable, remove defunct stubs]

Frequently asked questions

What is CVE-2026-46076?
In the Linux kernel, the following vulnerability has been resolved: KVM: nSVM: Raise #UD if unhandled VMMCALL isn't intercepted by L1 Explicitly synthesize a #UD for VMMCALL if L2 is active, L1 does NOT want to intercept VMMCALL, nested_svm_l2_tlb_flush_enabled() is true, and the hypercall is something other than one of the supported Hyper-V hypercalls. When all of the above conditions are met, KVM will intercept VMMCALL but never forward it to L1, i.e. will let L2 make hypercalls as if it were L1. The TLFS says a whole lot of nothing about this scenario, so go with the architectural behavior, which says that VMMCALL #UDs if it's not intercepted. Opportunistically do a 2-for-1 stub trade by stub-ifying the new API instead of the helpers it uses. The last remaining "single" stub will soon be dropped as well. [sean: rewrite changelog and comment, tag for stable, remove defunct stubs]
How severe is CVE-2026-46076?
CVE-2026-46076 has a CVSS 3.x base score of 7.9, rated high severity. It is exploitable over local access with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is low, integrity low, and availability high.
Is CVE-2026-46076 being actively exploited?
It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (2nd percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-46076?
CVE-2026-46076 affects Linux Linux Kernel. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2026-46076?
Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
Does CVE-2026-46076 have an EU (EUVD) identifier?
Yes. CVE-2026-46076 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-32458.
When was CVE-2026-46076 published?
CVE-2026-46076 was published on 2026-05-27 and last updated on 2026-06-24.

References

Affected products (1)

More vulnerabilities in Linux Linux Kernel

All CVEs affecting Linux Linux Kernel →