PT-2026-29485 · Linux+1 · Linux Kernel+1

Published 2026-04-01 · Updated 2026-04-02 · CVE-2026-23402

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 versions prior to 7.0.0-rc2-eafebd2d2ab0-sink-vm #319

Description The Linux kernel contains a flaw within the KVM component related to memory management. Specifically, the issue involves an incorrect sanity check when overwriting a shadow-present SPTE (shadow page table entry) with another SPTE having a different target PFN (page frame number). This check was only applied to direct MMUs (Memory Management Units), leaving systems without shadowed gPTEs vulnerable. While KVM itself cannot overwrite a shadow-present SPTE during a guest write, external writes from host userspace are not detected by KVM's write tracking, potentially breaking KVM's shadow paging rules.

Recommendations Update to a version newer than 7.0.0-rc2-eafebd2d2ab0-sink-vm #319.

Fix

Related Identifiers

CVE-2026-23402

Affected Products

Kvm

Linux Kernel

References · 12

• https://nvd.nist.gov/vuln/detail/CVE-2026-23402 · Security Note
• https://git.kernel.org/stable/c/bab090e8fd5607f77379ea78b9d0c683cb1538a9 · Patch
• https://ubuntu.com/security/CVE-2026-23402 · Vendor Advisory
• https://security-tracker.debian.org/tracker/CVE-2026-23402 · Vendor Advisory
• https://cve.org/CVERecord?id=CVE-2026-23402 · Security Note
• https://osv.dev/vulnerability/DEBIAN-CVE-2026-23402 · Vendor Advisory
• https://git.kernel.org/stable/c/df83746075778958954aa0460cca55f4b3fc9c02 · Patch
• https://git.kernel.org/stable/c/a1e0f7150639bc30a8e75476d1c7daab77d44992 · Patch
• https://osv.dev/vulnerability/UBUNTU-CVE-2026-23402 · Vendor Advisory
• https://git.kernel.org/linus/df83746075778958954aa0460cca55f4b3fc9c02 · Note
• https://twitter.com/CVEnew/status/2039279639047340532 · Twitter Post
• https://twitter.com/VulmonFeeds/status/2039388292190282058 · Twitter Post