PT-2026-37605 · Linux · Linux Kernel

Published 2026-05-06 · Updated 2026-05-15 · CVE-2026-43265

Positive Technologies (AI Summary)

CVSS v3.1

5.5

Medium

Base vector

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

Name of the Vulnerable Software and Affected Versions Linux kernel (affected versions not specified)

Description An issue exists in the KVM x86 component where the system fails to ignore -EBUSY when checking nested events from the vcpu block() function after exiting a blocking state while L2 is active. This can occur if userspace provides invalid MP STATE or injected events, placing the vCPU in an impossible state. Failure to ignore this error can trigger a spurious userspace exit, typically with KVM EXIT UNKNOWN, which may lead to the virtual machine crashing.

Recommendations At the moment, there is no information about a newer version that contains a fix for this vulnerability.

Related Identifiers

CVE-2026-43265

OESA-2026-2312

OESA-2026-2313

OESA-2026-2314

Affected Products

Linux Kernel

References · 42

• https://git.kernel.org/stable/c/ead63640d4e72e6f6d464f4e31f7fecb79af8869 · Patch
• https://nvd.nist.gov/vuln/detail/CVE-2026-31575 · Security Note
• https://nvd.nist.gov/vuln/detail/CVE-2026-43214 · Security Note
• https://git.kernel.org/stable/c/ec3be7dc9391085a2d96700e159d66d1328b7ff6 · Patch
• https://git.kernel.org/stable/c/2657439265d34a911886b916ba8be97ecc117d51 · Patch
• https://nvd.nist.gov/vuln/detail/CVE-2026-43018 · Security Note
• https://osv.dev/vulnerability/DEBIAN-CVE-2026-43265 · Vendor Advisory
• https://ubuntu.com/security/CVE-2026-43265 · Vendor Advisory
• https://git.kernel.org/stable/c/1c957773063ed3264953597e32990a748381caf6 · Patch
• https://osv.dev/vulnerability/OESA-2026-2313 · Vendor Advisory
• https://nvd.nist.gov/vuln/detail/CVE-2026-31625 · Security Note
• https://nvd.nist.gov/vuln/detail/CVE-2026-43017 · Security Note
• https://osv.dev/vulnerability/BELL-CVE-2026-43265 · Vendor Advisory
• https://nvd.nist.gov/vuln/detail/CVE-2026-31515 · Security Note
• https://osv.dev/vulnerability/UBUNTU-CVE-2026-43265 · Vendor Advisory