Answer in brief
CVE-2026-64561 records a High severity (CVSS 8.8) vulnerability in KVM: x86: Check for invalid/obsolete root *after* making MMU pages available. The current sources do not mark it as known exploited. The current feed maps Linux/Linux (generic), Linux/Linux (generic), Linux/Linux (generic), Linux/Linux (generic). Check affected ranges and fixed versions before updating.
Analysis pending evidence review
HOL Guard separates source facts from reviewed analysis. See the methodology.
CVSS is 8.8. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.
Analysis status
Analysis pending evidence review
Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.
The current feed maps Linux/Linux (generic), Linux/Linux (generic), Linux/Linux (generic), Linux/Linux (generic). Check affected ranges and fixed versions before updating.
| Package | Affected range | Fixed version |
|---|---|---|
| Linux/Linuxgeneric | >=f95eec9bed76d42194c23153cb1cc8f186bf91cb <35e77467610c4a37cb0ff54ee56b85f73b1f5700 || >=f95eec9bed76d42194c23153cb1cc8f186bf91cb <0026dbb7de8ea76e97d6edf42fc3cc084564e2bf || >=f95eec9bed76d42194c23153cb1cc8f186bf91cb <f3477a6a4164f15287444eda685b5f6405dbd1e5 || >=f95eec9bed76d42194c23153cb1cc8f186bf91cb <bce0d3c26e2c761a4bf43c8949f333fc7374eb2d || >=f95eec9bed76d42194c23153cb1cc8f186bf91cb <2abd5287f08319fa35764566b15c6e22cb1068db | 35e77467610c4a37cb0ff54ee56b85f73b1f5700, 0026dbb7de8ea76e97d6edf42fc3cc084564e2bf, f3477a6a4164f15287444eda685b5f6405dbd1e5, bce0d3c26e2c761a4bf43c8949f333fc7374eb2d, 2abd5287f08319fa35764566b15c6e22cb1068db |
| Linux/Linuxgeneric | >=f95eec9bed76d42194c23153cb1cc8f186bf91cb <65c4f7a1028cf01a93a2762d679c289810ede990 || >=f95eec9bed76d42194c23153cb1cc8f186bf91cb <35e77467610c4a37cb0ff54ee56b85f73b1f5700 || >=f95eec9bed76d42194c23153cb1cc8f186bf91cb <0026dbb7de8ea76e97d6edf42fc3cc084564e2bf || >=f95eec9bed76d42194c23153cb1cc8f186bf91cb <f3477a6a4164f15287444eda685b5f6405dbd1e5 || >=f95eec9bed76d42194c23153cb1cc8f186bf91cb <bce0d3c26e2c761a4bf43c8949f333fc7374eb2d || >=f95eec9bed76d42194c23153cb1cc8f186bf91cb <2abd5287f08319fa35764566b15c6e22cb1068db | 65c4f7a1028cf01a93a2762d679c289810ede990, 35e77467610c4a37cb0ff54ee56b85f73b1f5700, 0026dbb7de8ea76e97d6edf42fc3cc084564e2bf, f3477a6a4164f15287444eda685b5f6405dbd1e5, bce0d3c26e2c761a4bf43c8949f333fc7374eb2d, 2abd5287f08319fa35764566b15c6e22cb1068db |
| Linux/Linuxgeneric | 5.9 | Not reported |
| Linux/Linuxgeneric | >=f95eec9bed76d42194c23153cb1cc8f186bf91cb <62ef67af1878fa2cd066642f2f59e33ade95f637 || >=f95eec9bed76d42194c23153cb1cc8f186bf91cb <65c4f7a1028cf01a93a2762d679c289810ede990 || >=f95eec9bed76d42194c23153cb1cc8f186bf91cb <35e77467610c4a37cb0ff54ee56b85f73b1f5700 || >=f95eec9bed76d42194c23153cb1cc8f186bf91cb <0026dbb7de8ea76e97d6edf42fc3cc084564e2bf || >=f95eec9bed76d42194c23153cb1cc8f186bf91cb <f3477a6a4164f15287444eda685b5f6405dbd1e5 || >=f95eec9bed76d42194c23153cb1cc8f186bf91cb <bce0d3c26e2c761a4bf43c8949f333fc7374eb2d || >=f95eec9bed76d42194c23153cb1cc8f186bf91cb <2abd5287f08319fa35764566b15c6e22cb1068db | 62ef67af1878fa2cd066642f2f59e33ade95f637, 65c4f7a1028cf01a93a2762d679c289810ede990, 35e77467610c4a37cb0ff54ee56b85f73b1f5700, 0026dbb7de8ea76e97d6edf42fc3cc084564e2bf, f3477a6a4164f15287444eda685b5f6405dbd1e5, bce0d3c26e2c761a4bf43c8949f333fc7374eb2d, 2abd5287f08319fa35764566b15c6e22cb1068db |
Published upstream
Aug 4, 2026
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Nov 3, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Aug 4, 2026
In the Linux kernel, the following vulnerability has been resolved: KVM: x86: Check for invalid/obsolete root *after* making MMU pages available Check for a "stale" page fault, i.e. for an invalid and/or obsolete root, after making MMU pages available for the shadow MMU. If reclaiming shadow pages zaps an in-use root, i.e. marks it invalid, then KVM will attempt to map memory into an invalid root. On its own, populating an invalid root is "fine", but because child shadow pages inherit their parent's role, any children created during the map/fetch will be created as invalid pages, thus violating KVM's invariant that invalid pages are never on the list of active MMU pages. Note, the underlying flaw has existed since KVM first started tracking invalid roots in 2008 (commit 2e53d63acba7, "KVM: MMU: ignore zapped root pagetables"), but the true badness only came along in 2020 (Linux 5.9) with the invariant that invalid shadow pages can't be on the list of active pages. Note #2, inheriting role.invalid when creating child shadow pages is also far from ideal; that flaw will be addressed separately.
Quoted source text, attributed separately from HOL analysis.