Kernel panic via NULL HugeTLB CMA nodemask
Published Sep 16, 2026 · Updated Sep 16, 2026
NULL pointer dereference in Linux 6.19 allows local users to crash the kernel through a crafted gigantic hugepage allocation. hugetlb_cma_alloc_frozen_folio dereferences a NULL nodemask propagated through the gigantic-page fallback in its node checks and iteration. Exploitation requires HugeTLB CMA on only some NUMA nodes, an unreserved gigantic page, and MPOL_PREFERRED_MANY; the resulting fault panics the host.
Summary
What happened
NULL pointer dereference in Linux 6.19 allows local users to crash the kernel through a crafted gigantic hugepage allocation. hugetlb_cma_alloc_frozen_folio dereferences a NULL nodemask propagated through the gigantic-page fallback in its node checks and iteration. Exploitation requires HugeTLB CMA on only some NUMA nodes, an unreserved gigantic page, and MPOL_PREFERRED_MANY; the resulting fault panics the host.
The record
- CVE
- CVE-2026-89966
- Published
- Sep 16, 2026
- Updated
- Sep 16, 2026
- Vendor
- The Linux Kernel Organization
- Product
- Linux
- Classifications
- T1499.004
- Attack vector
- local
- Privileges
- authenticated
Timeline
How it unfolded
- Sep 16, 2026CVE publishedPublication date reported by the CVE source.
- Sep 16, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=6.19
- Affected versionversion=eb02f14c4a2bf4c242d91c4a5d7fb57c3c0ad1b1 <10f616ef06c5bd2d656a0eebaf73f9b09d150c24
- Affected versionversion=eb02f14c4a2bf4c242d91c4a5d7fb57c3c0ad1b1 <7b8a8ae4dd176a232e973017d2aa3c536a7275e2
What conditions does exploitation require?
What is affected?
Published CVSS scores
No CVSS assessment is available in this record.
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Weakness, pattern, technique
Public exploit references
- Upstream HugeTLB CMA kernel-panic reproducerproof of concept · demonstrated
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Technologies
Your stack
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Your stack
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