CVE-2026-53359: Linux kernel · KVM: x86: Fix shadow paging use-after-free due to unexpected role
Source GCVE Database
Not known to be exploited · CVSS 8.8 High.
Data as of 26 Oct 2026, 17:16 UTC
- EPSS
- 1.3% chance of exploitation in 30 days – higher than 71% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:HExploitation evidence
Disclosed: evidence found.
CVE published 4 Jul 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.
What to do
AI-suggested
Red Hat has released official live patch updates (kpatch-patch-4_18_0-477_97_1 and related versions) for Red Hat Enterprise Linux 8.8 to address this vulnerability. Users should apply these kpatch live patches as per Red Hat's guidance to remediate the issue. For detailed instructions on applying the update, refer to https://access.redhat.com/articles/11258. Since this is a live patch, it can be applied without rebooting the system. Patch status is confirmed as available and official.
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.
References
- access.redhat.com/errata/RHSA-2026:43847 (opens in a new tab)
- access.redhat.com/security/updates/classification/ (opens in a new tab)
- bugzilla.redhat.com/show_bug.cgi?id=2497033 (opens in a new tab)
- security.access.redhat.com/data/csaf/v2/advisories/2026/rhsa-2026_43847.json (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:44004 (opens in a new tab)
- security.access.redhat.com/data/csaf/v2/advisories/2026/rhsa-2026_44004.json (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:44003 (opens in a new tab)
- security.access.redhat.com/data/csaf/v2/advisories/2026/rhsa-2026_44003.json (opens in a new tab)
- suse.com/support/security/rating/ (opens in a new tab)
- ftp.suse.com/pub/projects/security/csaf/opensuse-su-2026_11214-1.json (opens in a new tab)
- suse.com/security/cve/CVE-2026-53359/ (opens in a new tab)
- suse.com/security/cve/CVE-2026-53362/ (opens in a new tab)
- ftp.suse.com/pub/projects/security/csaf/suse-su-2026_22982-1.json (opens in a new tab)
- suse.com/support/update/announcement/2026/suse-su-202622982-1/ (opens in a new tab)
- lists.suse.com/pipermail/sle-security-updates/2026-August/028082.html (opens in a new tab)
- bugzilla.suse.com/1270060 (opens in a new tab)
- bugzilla.suse.com/1271370 (opens in a new tab)
- suse.com/security/cve/CVE-2026-53366/ (opens in a new tab)
- nvd.nist.gov/vuln/detail/CVE-2026-53359 (opens in a new tab)
- git.kernel.org/stable/c/0b5e8ead71e683bcf6232db16234cf7e6d553a23 (opens in a new tab)
- git.kernel.org/stable/c/1ae7d5a6db6c190ce183e3098ca0e0846e14d462 (opens in a new tab)
- git.kernel.org/stable/c/2ad3afa40ac6aa340dada122f9abfa46c0a6eb35 (opens in a new tab)
- git.kernel.org/stable/c/5e470998a23e4c3d89ed24e8172cb22747e61efa (opens in a new tab)
- git.kernel.org/stable/c/81ccda30b4e83d8f5cc4fd50503c44e3a33abfeb (opens in a new tab)
- git.kernel.org/stable/c/9291654d69e08542de37755cebe4d5b02c3170d1 (opens in a new tab)
- git.kernel.org/stable/c/b1337aae5e194324e4810d561764e7793f8b3864 (opens in a new tab)
- github.com/V4bel/Januscape/blob/main/assets/write-up.md (opens in a new tab)
- openwall.com/lists/oss-security/2026/07/06/7 (opens in a new tab)