# CVE-2026-53359: KVM: x86: Fix shadow paging use-after-free due to unexpected role

> CVE-2026-53359: KVM: x86: Fix shadow paging use-after-free due to unexpected role. CVSS 8.8 (CVSS 3.1).

Canonical: https://rewindex.com/cve/CVE-2026-53359
Last updated: 2026-10-03T11:17:35Z

- Published: 2026-07-04 11:51 UTC · Updated: 2026-10-03 11:17 UTC · Assigner: Linux
- CVSS: 8.8 (CVSS 3.1) · Severity: High · Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H
- EPSS: 1.4%, 72th percentile (scored 2026-10-25)
- CISA KEV: no

## Description

In the Linux kernel, the following vulnerability has been resolved: KVM: x86: Fix shadow paging use-after-free due to unexpected role Commit 0cb2af2ea66ad ("KVM: x86: Fix shadow paging use-after-free due to unexpected GFN") fixed a shadow paging mismatch between stored and computed GFNs; the bug could be triggered by changing a PDE mapping from outside the guest, and then deleting a memslot.  The rmap\_remove() call would miss entries created after the PDE change because the GFN of the leaf SPTE does not match the GFN of the struct kvm\_mmu\_page. A similar hole however remains if the modified PDE points to a non-leaf page.  In this case the gfn can be made to match, but the role does not match: the original large 2MB page creates a kvm\_mmu\_page with direct=1, while the new 4KB needs a kvm\_mmu\_page with direct=0.  However, kvm\_mmu\_get\_child\_sp() does not compare the role, and therefore reuses the page. The next step is installing a leaf (4KB) SPTE on the new path which records an rmap entry under the gfn resolved by the walk.  But when that child is zapped its parent kvm\_mmu\_page has direct=1 and kvm\_mmu\_page\_get\_gfn() computes the gfn for the 4KB page as sp-\>gfn + index instead of using sp-\>shadowed\_translation\[\] (or sp-\>gfns\[\] in older kernels).  It therefore fails to remove the recorded entry. When the memslot is dropped the shadow page is freed but the rmap entry survives, as in the scenario that was already fixed.  Code that later walks that gfn (dirty logging, MMU notifier invalidation, and so on) dereferences an sptep that lies in the freed page, causing the use-after-free.

## Affected vendors and products

- Linux: Linux

## Tracked companies

- [Google Cloud](https://rewindex.com/company/google-cloud.md)

## References

- [CVE record on cve.org](https://www.cve.org/CVERecord?id=CVE-2026-53359)
- [NVD entry](https://nvd.nist.gov/vuln/detail/CVE-2026-53359)
- [https://git.kernel.org/stable/c/0b5e8ead71e683bcf6232db16234cf7e6d553a23](https://git.kernel.org/stable/c/0b5e8ead71e683bcf6232db16234cf7e6d553a23)
- [https://git.kernel.org/stable/c/1ae7d5a6db6c190ce183e3098ca0e0846e14d462](https://git.kernel.org/stable/c/1ae7d5a6db6c190ce183e3098ca0e0846e14d462)
- [https://git.kernel.org/stable/c/2ad3afa40ac6aa340dada122f9abfa46c0a6eb35](https://git.kernel.org/stable/c/2ad3afa40ac6aa340dada122f9abfa46c0a6eb35)
- [https://git.kernel.org/stable/c/5e470998a23e4c3d89ed24e8172cb22747e61efa](https://git.kernel.org/stable/c/5e470998a23e4c3d89ed24e8172cb22747e61efa)
- [https://git.kernel.org/stable/c/81ccda30b4e83d8f5cc4fd50503c44e3a33abfeb](https://git.kernel.org/stable/c/81ccda30b4e83d8f5cc4fd50503c44e3a33abfeb)
- [https://git.kernel.org/stable/c/9291654d69e08542de37755cebe4d5b02c3170d1](https://git.kernel.org/stable/c/9291654d69e08542de37755cebe4d5b02c3170d1)
- [https://git.kernel.org/stable/c/b1337aae5e194324e4810d561764e7793f8b3864](https://git.kernel.org/stable/c/b1337aae5e194324e4810d561764e7793f8b3864)

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_Sources: CVE records from the CVE Program (cve.org). CVE® is a registered trademark of The MITRE Corporation. (https://www.cve.org/) This product uses data from the NVD API but is not endorsed or certified by the NVD. (https://nvd.nist.gov/) Known Exploited Vulnerabilities catalog from CISA. (https://www.cisa.gov/known-exploited-vulnerabilities-catalog) EPSS scores from FIRST (Exploit Prediction Scoring System). (https://www.first.org/epss/)_


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Canonical: https://rewindex.com/cve/CVE-2026-53359 · Markdown: https://rewindex.com/cve/CVE-2026-53359.md · JSON: https://rewindex.com/api/v1/cves/CVE-2026-53359 · Data licensed CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/) · Generated 2026-10-26T03:10:11.233Z