CVE-2026-53359: CVE-2026-53359: In the Linux kernel, the following vulnerability has been resolved: KVM: x86: Fix shadow …
linux · linux kernel · NVD published 2026-07-04 · posted 2026-07-07 · last modified 2026-10-03
What it is
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.
| Weakness | CWE-416 |
|---|---|
| CVSS vector | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H (source: 416baaa9-dc9f-4396-8d5f-8c081fb06d67) |
| ATT&CK tactics | Execution |
Exploitation evidence
First exploit evidence seen: 2026-07-07 (earliest date across the sources below).
Exploited in the wild
No source on this site lists in-the-wild exploitation yet (CISA KEV, VulnCheck KEV).
Public exploit code
GitHub proof-of-concept repositories
7 public repositories from 7 accounts, first seen 2026-07-07. Most starred: Aoripus-LTD/Januscape-Hotfix (6 stars), view repository.
Verify before running: public PoCs can be malicious. Read the code and only run it in an isolated lab. A PoC means exploit code is public, not that this CVE is exploited in the wild.
Sources: nomi-sec/PoC-in-GitHub.
How to fix it
Fixed versions
- linux linux kernel: upgrade to 6.1.177 or later (affected from 2.6.36)
- linux linux kernel: upgrade to 6.6.144 or later (affected from 6.2)
- linux linux kernel: upgrade to 6.12.95 or later (affected from 6.7)
- linux linux kernel: upgrade to 6.18.38 or later (affected from 6.13)
- linux linux kernel: upgrade to 7.1.3 or later (affected from 6.19)
Derived from the NVD CPE configuration (versionEndExcluding / versionEndIncluding). Always confirm with the vendor advisory.
Vendor advisories and patches
- https://git.kernel.org/stable/c/1ae7d5a6db6c190ce183e3098ca0e0846e14d462 (Patch)
- https://git.kernel.org/stable/c/2ad3afa40ac6aa340dada122f9abfa46c0a6eb35 (Patch)
- https://git.kernel.org/stable/c/5e470998a23e4c3d89ed24e8172cb22747e61efa (Patch)
- https://git.kernel.org/stable/c/81ccda30b4e83d8f5cc4fd50503c44e3a33abfeb (Patch)
- https://git.kernel.org/stable/c/9291654d69e08542de37755cebe4d5b02c3170d1 (Patch)
- https://git.kernel.org/stable/c/b1337aae5e194324e4810d561764e7793f8b3864 (Patch)
MITRE ATT&CK mitigations for this chain
- M1050 Exploit Protection (for T1203) : Security applications that look for behavior used during exploitation such as Windows Defender Exploit Guard (WDEG) and the Enhanced Mitigation Experience Toolkit (EMET) can be used to mitigate some exploitation behavior. Control flow integrity checking is another way to potentially identify and stop a software exploi
- M1051 Update Software (for T1203) : Perform regular software updates to mitigate exploitation risk. Keeping software up-to-date with the latest security patches helps prevent adversaries from exploiting known vulnerabilities in client software, reducing the risk of successful attacks.
- M1048 Application Isolation and Sandboxing (for T1203) : Browser sandboxes can be used to mitigate some of the impact of exploitation, but sandbox escapes may still exist. Other types of virtualization and application microsegmentation may also mitigate the impact of client-side exploitation. Risks of additional exploits and weaknesses in those systems may still exist.
Detection Generic guidance
- Execution: Watch for the service process spawning shells or script interpreters (cmd.exe, powershell, sh, bash, python) via EDR process-tree rules.
Response checklist Generic guidance
- Inventory: find every instance of the affected product and version (include internet-facing and forgotten ones).
- Patch or mitigate per the vendor advisory; if you cannot patch, remove internet exposure or apply the vendor workaround.
- Assume compromise if the system was exposed before patching: hunt for the indicators in the advisory and review logs back to the disclosure date.
- Rotate credentials and secrets stored on or used by the affected system if compromise cannot be ruled out.