Guest-to-host compromise via stale shadow-page reverse map
Published May 28, 2026 · Updated May 28, 2026
Use-after-free in affected Linux Kernel KVM releases allows guest OS users to corrupt host memory via guest page-table changes. KVM shadow-MMU code treats a present shadow page as belonging to the expected guest frame number, so rmap_remove() misses an out-of-range reverse-map entry and a later rmap walk dereferences the freed kvm_mmu_page. Exploitation requires low-privileged guest access, shadow paging, a mapping change between VM entries, memslot deletion, and a later reverse-map walk; the resulting host-kernel memory corruption can expose or alter data or crash the host.
Summary
What happened
Use-after-free in affected Linux Kernel KVM releases allows guest OS users to corrupt host memory via guest page-table changes. KVM shadow-MMU code treats a present shadow page as belonging to the expected guest frame number, so rmap_remove() misses an out-of-range reverse-map entry and a later rmap walk dereferences the freed kvm_mmu_page. Exploitation requires low-privileged guest access, shadow paging, a mapping change between VM entries, memslot deletion, and a later reverse-map walk; the resulting host-kernel memory corruption can expose or alter data or crash the host.
The record
- CVE
- CVE-2026-46113
- Published
- May 28, 2026
- Updated
- May 28, 2026
- Vendor
- The Linux Kernel Organization
- Product
- Linux Kernel
- Classifications
- CWE-416, T1068
- Attack vector
- local
- Privileges
- authenticated
Timeline
How it unfolded
- May 28, 2026CVE publishedPublication date reported by the CVE source.
- May 28, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=2.6.20
- Affected versionversion=6aa8b732ca01c3d7a54e93f4d701b8aabbe60fb7 <06c19c967b845b63172601fe459667d973b7e6b7
- Affected versionversion=6aa8b732ca01c3d7a54e93f4d701b8aabbe60fb7 <0cb2af2ea66ad8ff195c156ea690f11216285bdf
- Affected versionversion=6aa8b732ca01c3d7a54e93f4d701b8aabbe60fb7 <14d1e55dfd2cf4711bff164a6aaaddb783552134
- Affected versionversion=6aa8b732ca01c3d7a54e93f4d701b8aabbe60fb7 <488e386484ec8c0e558be6e156edf34ed9f4d5c8
- Affected versionversion=6aa8b732ca01c3d7a54e93f4d701b8aabbe60fb7 <738ec97b1855df6c08fe2369f798fa0b972e556b
What conditions does exploitation require?
What is affected?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Public exploit references
No public exploit references are available in this record.
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Technologies
Your stack
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Your stack
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