Local hugetlb swap-entry corruption via wrong bit clear
Published Sep 4, 2026 · Updated Sep 4, 2026
Memory corruption in the Linux kernel allows local users to corrupt a child process's hugetlb swap entry during fork(). copy_hugetlb_page_range() uses huge_pte_clear_uffd_wp(), which clears a present-PTE bit position inside the nonpresent swap payload, advancing an encoded PFN by two pages on x86-64. A plain fork() must coincide with an in-flight hugetlb migration entry or a poisoned huge page; the skew is usually latent but can propagate when the corrupted offset is re-encoded.
Summary
What happened
Memory corruption in the Linux kernel allows local users to corrupt a child process's hugetlb swap entry during fork(). copy_hugetlb_page_range() uses huge_pte_clear_uffd_wp(), which clears a present-PTE bit position inside the nonpresent swap payload, advancing an encoded PFN by two pages on x86-64. A plain fork() must coincide with an in-flight hugetlb migration entry or a poisoned huge page; the skew is usually latent but can propagate when the corrupted offset is re-encoded.
The record
- CVE
- CVE-2026-80893
- Published
- Sep 4, 2026
- Updated
- Sep 4, 2026
- Vendor
- The Linux Kernel Organization
- Product
- Linux
- Classifications
- Unavailable
- Attack vector
- local
- Privileges
- authenticated
Timeline
How it unfolded
- Sep 4, 2026CVE publishedPublication date reported by the CVE source.
- Sep 4, 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=5.19
- Affected versionversion=bc70fbf269fdff410b0b6d75c3770b9f59117b90 <2b9a07002c2f296aa6a9c591213933d3492e3089
- Affected versionversion=bc70fbf269fdff410b0b6d75c3770b9f59117b90 <2fa11c60c9c06bafc19cf4d9efdaa36a38079e87
- Affected versionversion=bc70fbf269fdff410b0b6d75c3770b9f59117b90 <69cb5825d9988c7944bc9f1dc08cb233655405a7
- Affected versionversion=bc70fbf269fdff410b0b6d75c3770b9f59117b90 <83abe2fd5b3aeb3123b5408a5a91709c5538fb23
- Affected versionversion=bc70fbf269fdff410b0b6d75c3770b9f59117b90 <8b0de7005b148738d79d6c45594d566489948a68
- Affected versionversion=bc70fbf269fdff410b0b6d75c3770b9f59117b90 <f1b1311c0352873137768bac5a126e491271a747
What conditions does exploitation require?
What is affected?
Published CVSS scores
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Attacks
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Weakness, pattern, technique
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Public exploit references
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Technologies
Your stack
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Your stack
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