VulnerabilityPublished 10 Aug 2026Updated 6 Nov 2026

CVE-2026-68428: Linux kernel · KVM: x86/mmu: Fix use-after-free on vendor module reload

Affects Linux kernelSource CVE Database V5

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Not known to be exploited · fixed in ec9daa8fd1b6f45545c9839dca55bd867fad9e13 : update Linux kernel when convenient.

Data as of 6 Nov 2026, 17:04 UTC

Severity

Unrated

Rated by Threat Radar · No CVSS score from NVD or the CNA

Thin evidence

One scorer or none

Exploitation: No evidence of active exploitation and no public proof of concept
Automatable: Attackers cannot reliably automate steps 1–4 of the kill chain
Technical impact: Limited control over the software or limited information exposure

CISA SSVC assessment, 2026-11-06.

Patch

Available – fixed in ec9daa8fd1b6f45545c9839dca55bd867fad9e13, 940950d5cd86f250dca578279ad5ca63b4e0986b, 42272b0f239f3a89f9c26a01cc37aee06138b1b7 +5

Exploitation evidence

Disclosed: evidence found.
CVE published 10 Aug 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: 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 6 Nov 2026.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponized: A Metasploit exploit module or Exploit-DB entry exists (Metasploit scanner modules do not count), or CISA SSVC or the CVSS exploit maturity reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

What to do

Upgrade to a fixed release listed under Affected software.

Affected software

Product	Affected	Fixed in
LinuxLinux	Affected ≥ cb498ea2ce1d3f3c0bc0a2522241dca10263e437, < ec9daa8fd1b6f45545c9839dca55bd867fad9e13	Fixed in ec9daa8fd1b6f45545c9839dca55bd867fad9e13
LinuxLinux	Affected ≥ cb498ea2ce1d3f3c0bc0a2522241dca10263e437, < 940950d5cd86f250dca578279ad5ca63b4e0986b	Fixed in 940950d5cd86f250dca578279ad5ca63b4e0986b
LinuxLinux	Affected ≥ cb498ea2ce1d3f3c0bc0a2522241dca10263e437, < 42272b0f239f3a89f9c26a01cc37aee06138b1b7	Fixed in 42272b0f239f3a89f9c26a01cc37aee06138b1b7
LinuxLinux	Affected ≥ cb498ea2ce1d3f3c0bc0a2522241dca10263e437, < 52f2f7c30126037975389aa04d24c506a5177c35	Fixed in 52f2f7c30126037975389aa04d24c506a5177c35
LinuxLinux	Affected ≥ cb498ea2ce1d3f3c0bc0a2522241dca10263e437, < 43cfb20d62ffe49626d62beecfc32eb6f262191c	Fixed in 43cfb20d62ffe49626d62beecfc32eb6f262191c
LinuxLinux	Affected ≥ cb498ea2ce1d3f3c0bc0a2522241dca10263e437, < 034b7fa1f5846d69eb51f12ce6d1c71871e83c2d	Fixed in 034b7fa1f5846d69eb51f12ce6d1c71871e83c2d

Description

In the Linux kernel, the following vulnerability has been resolved: KVM: x86/mmu: Fix use-after-free on vendor module reload mmu_destroy_caches() destroys pte_list_desc_cache and mmu_page_header_cache, but leaves both pointers unchanged. The pointers live in kvm.ko, and therefore survive when a vendor module is unloaded while kvm.ko remains loaded. If creation of pte_list_desc_cache fails during a subsequent vendor module load, its assignment sets pte_list_desc_cache to NULL and the error path calls mmu_destroy_caches(). mmu_page_header_cache still points to the cache destroyed during the preceding vendor module unload. Passing that stale pointer to kmem_cache_destroy() causes a slab use-after-free. Reproduce the issue on a v7.1.3 kernel with CONFIG_KASAN=y, CONFIG_KASAN_GENERIC=y, CONFIG_KVM=m, and CONFIG_KVM_INTEL=m. A one-shot test hook forces pte_list_desc_cache to NULL on the second invocation of kvm_mmu_vendor_module_init(): 1. Load kvm.ko and kvm-intel.ko, creating both caches. 2. Unload only kvm_intel, leaving kvm.ko loaded. 3. Reload kvm_intel and force initialization through the -ENOMEM path. KASAN reports: BUG: KASAN: slab-use-after-free in kvm_mmu_vendor_module_init+0x5b/0x170 [kvm] ... kmem_cache_destroy+0x21/0x1d0 kvm_mmu_vendor_module_init+0x5b/0x170 [kvm] ... Allocated by task 16817: __kmem_cache_create_args+0x12c/0x3b0 __kmem_cache_create.constprop.0+0xb6/0xf0 [kvm] kvm_mmu_vendor_module_init+0x13b/0x170 [kvm] ... Freed by task 16820: kmem_cache_destroy+0x117/0x1d0 kvm_mmu_vendor_module_exit+0x21/0x30 [kvm] Clear both pointers immediately after destroying their caches so that the stored state reflects the caches' lifetime and repeated cleanup is safe. With the fix applied, the same injected vendor module reload fails with -ENOMEM as expected and produces no KASAN report.

References

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