CVE-2026-98468: KVM: arm64: Fix spurious warning for benign stage 2 teardown race
Noroxi assessment
Priority: Monitor (action score 0/100)
- The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
- Probability of exploitation in the next 30 days: 0.20% (FIRST EPSS).
- Fixed version: Linux Linux 330346dda3bf5f8a3b06723024f7d906326270cf, 38b70fc453c3112f1a62583b89903ae41116cc27, c23ed110d27ba99cf3a881986514f79aacedf476.
- Mentioned 1 time in Turkish national cyber security advisories (siberguvenlik.gov.tr).
Low priority for now. Upgrade to Linux Linux 330346dda3bf5f8a3b06723024f7d906326270cf, 38b70fc453c3112f1a62583b89903ae41116cc27, c23ed110d27ba99cf3a881986514f79aacedf476 or later.
Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it
Primary sources: NVD · CVE.org · FIRST EPSS
In the Linux kernel, the following vulnerability has been resolved: KVM: arm64: Fix spurious warning for benign stage 2 teardown race kvmtool was used to establish an L1 guest with 8 CPUs and 8 GiB of RAM, an L2 guest with 4 CPUs and 4 GiB of RAM and an L3 guest with 2 CPUs and 2 GiB of RAM, all of which was then exited. Under memory pressure in the L0 host warnings were observed due to migration triggered by compaction: WARNING: arch/arm64/kvm/mmu.c:336 at __unmap_stage2_range+0x64/0x80, CPU#5: kcompactd0/66 Which was, in turn, triggered by an MMU notifier for the host invalidation: mmu_notifier_invalidate_range_start() -> ... -> kvm_mmu_notifier_invalidate_range_start() -> kvm_mmu_unmap_gfn_range() -> kvm_unmap_gfn_range() -> kvm_nested_s2_unmap() -> kvm_stage2_unmap_range() -> __unmap_stage2_range() -> stage2_apply_range() <- -EINVAL, triggering a WARN_ON() Racing with L0's teardown of stage 2 page tables: exit_mm() -> mmput() -> __mmput() -> exit_mmap() -> mmu_notifier_release() -> ... -> kvm_mmu_notifier_release() -> kvm_flush_shadow_all() -> kvm_arch_flush_shadow_all() -> kvm_free_stage2_pgd() -> [ acquire kvm->mmu_lock for write ] -> mmu->pgt = NULL [ among other tasks ] -> [ release kvm->mmu_lock for write ] It turns out there is a benign race resulting in a spurious warning: Thread A - notify: migration | Thread B - notify: release -------------------------------|--------------------------------- < kvm->mmu_lock held > | stage2_apply_range() | get mmu->pgt, check !NULL | ... | kvm_arch_flush_shadow_all() cond_resched_rwlock_write(); | < contend, sleep kvm->mmu_lock > < drop kvm->mmu_lock > | < acquire kvm->mmu_lock> | ... | kvm_free_stage2_pgd() | mmu->pgt = NULL | < invalidate MMU > | ... | < release kvm->mmu_lock > [ scheduled ] | stage2_apply_range() | < loop to next > | get, mmu->pgt, check !NULL | is NULL, return -EINVAL | __unmap_stage2_range() | WARN_ON(-EINVAL) <--- entirely spurious - the race was handled correctly. Fix the spurious warning by updating stage2_apply_range() to no longer treat concurrent PGT teardown on lock release as an error - whether the walker is tearing down page tables or doing something else this is a legitimate reason to abort the operation without error. This keeps the warning in place for all other circumstances. In practice only __unmap_stage2_range() actually does anything with the error so this only impacts that.
- Published
- Oct 18, 2026
- Updated
- Oct 19, 2026
- EPSS
- 0.2% · 10th percentile
- CWE
- —
Report tools
Action score
0
Monitor
Low priority for now.
- CVSS
- 0 / 40 · —
- CISA KEV
- 0 / 30 · Not listed
- EPSS
- 0 / 30 · 0.2%
Get told when this record changes
- Not in KEV: no record of exploitation in the wild
- No public exploit code on record
- A fix has been released
If any of these changes, we'll tell you in the daily email digest.
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Noroxi analysis
What does it mean in your environment?
The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.
We use this product, ask for helpAffected systems
Is your version affected?
Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.
—
Versions reported by the vendor
Affected version ranges reported by the assigning authority (Linux). Independent of NVD's CPE analysis and usually ahead of it.
Linux Linux
- 6.11affected
- ec14c272408af43d392f65f55e66f3b94fc61921 and later · before f44a92633136b409ebb9b7036fceb7e11de60a20affected · git
- ec14c272408af43d392f65f55e66f3b94fc61921 and later · before c23ed110d27ba99cf3a881986514f79aacedf476affected · git
- ec14c272408af43d392f65f55e66f3b94fc61921 and later · before 330346dda3bf5f8a3b06723024f7d906326270cfaffected · git
- ec14c272408af43d392f65f55e66f3b94fc61921 and later · before 38b70fc453c3112f1a62583b89903ae41116cc27affected · git
- before 6.11not affected · semver
- 6.12.112 and later · up to and including 6.12.*not affected · semver
- 6.18.55 and later · up to and including 6.18.*not affected · semver
- 7.2.9 and later · up to and including 7.2.*not affected · semver
- 7.3 and laternot affected · original_commit_for_fix
Package-level exposure
OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.
| Ecosystem | Package | Affected range | Fix |
|---|---|---|---|
| Debian:12 | linux-6.12 | before 6.12.113-1~deb12u1 | 6.12.113-1~deb12u1 |
| Debian:13 | linux | before 6.12.113-1 | 6.12.113-1 |
| Debian:14 | linux | before 7.2.9-1 | 7.2.9-1 |
Same product
linux: all recordsOther highest-scoring records for the same primary product.
- CVE-2026-74705udp: fix potential use-after-free in tunnel segmentation40Plan
- CVE-2026-74612veth: fix skb length accounting after XDP frag adjustment40Plan
- CVE-2026-74475vxlan: use neigh_ha_snapshot() in route_shortcircuit()40Plan
Published before and after this one in the same product
- ← EarlierCVE-2026-98466Oct 18, 2026 · KVM: arm64: Transfer the hyp stack pages out of the host stage-232Monitor
- ← EarlierCVE-2026-98467Oct 18, 2026 · KVM: arm64: nv: Fix null ptr deref on nested wp/unmap, teardown race0Monitor
- Later →CVE-2026-98469Oct 18, 2026 · KVM: arm64: Fix AArch32 DBGBXVR<n> handling28Monitor
Remediation
Which version to upgrade to
Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.
| Product / package | Fixed version | Source |
|---|---|---|
| Linux Linux | 330346dda3bf5f8a3b06723024f7d906326270cf | Vendor (CNA) |
| Linux Linux | 38b70fc453c3112f1a62583b89903ae41116cc27 | Vendor (CNA) |
| Linux Linux | c23ed110d27ba99cf3a881986514f79aacedf476 | Vendor (CNA) |
| Linux Linux | f44a92633136b409ebb9b7036fceb7e11de60a20 | Vendor (CNA) |
| debian:linux | 6.12.113-1 · Debian:13 | Package registry (OSV) |
| debian:linux-6.12 | 6.12.113-1~deb12u1 · Debian:12 | Package registry (OSV) |
Exploit status
No known public exploit
No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.
Research context
For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.
Timeline
From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.
- Published
- Fix recordedsame day
- TodayNov 8, 2026+21 d
FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).
Patch and commit links
Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.
No commit or PR link among the references.
Credits
All researchersFinders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.
No credits in the CNA record.
Variant candidates
Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.
No nightly-computed relations.
Chain candidates
An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.
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Bug bounty scope
No known public program.
Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).
National notice (Türkiye Cybersecurity Directorate / USOM)
Official security notices citing this record; remediation advice is on the agency's page.
- TR-26-1351 · Oct 19, 2026(Linux Kernel Güvenlik Bildirimi)
Technical details
No CVSS vector for this record, so attack conditions can't be derived.
Weakness class (CWE)
—
Attack context
MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.
MITRE has no CAPEC/ATT&CK mapping for this CWE.
Change log
- Exploit maturity— → none
- Fix✗ → ✓
For records you follow, these changes also arrive as notifications. →
References
Show all references (3 more)Show less
Vendor advisories and official records. Exploit/PoC links are deliberately left out.