Out-of-bounds write via truncated folio size
Published Sep 4, 2026 · Updated Sep 4, 2026
Out-of-bounds access in the Linux kernel allows local users to corrupt memory through a crafted io_uring registered buffer. In io_vec_fill_bvec(), shifting an int-sized 1 by a folio shift of at least 32 truncates the computed folio size, causing the fill loop to overrun the segment array and read beyond the source bvec array. Reachability requires a gigantic hugetlb page, such as a 16 GB page on arm64 with 64 KB base pages or a corresponding powerpc configuration; x86_64 is unaffected.
Summary
What happened
Out-of-bounds access in the Linux kernel allows local users to corrupt memory through a crafted io_uring registered buffer. In io_vec_fill_bvec(), shifting an int-sized 1 by a folio shift of at least 32 truncates the computed folio size, causing the fill loop to overrun the segment array and read beyond the source bvec array. Reachability requires a gigantic hugetlb page, such as a 16 GB page on arm64 with 64 KB base pages or a corresponding powerpc configuration; x86_64 is unaffected.
The record
- CVE
- CVE-2026-80810
- Published
- Sep 4, 2026
- Updated
- Sep 4, 2026
- Vendor
- The Linux Kernel Organization
- Product
- Linux
- Classifications
- Unavailable
- Attack vector
- local
- Privileges
- Unavailable
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=6.15
- Affected versionversion=9ef4cbbcb4ac3786a1a4164507511b76b2a572c5 <3267d7c8ba51642117f7bdd1ece02b2540668476
- Affected versionversion=9ef4cbbcb4ac3786a1a4164507511b76b2a572c5 <3f3a6a16bbe8bde76532d9415438f8cdef439e5d
- Affected versionversion=9ef4cbbcb4ac3786a1a4164507511b76b2a572c5 <45c945107e007b1fb73e21cd220277652a45521a
- Affected versionversion=9ef4cbbcb4ac3786a1a4164507511b76b2a572c5 <6b308c37fbeba3aa8c634fb1ed53e2f63a5d5a5c
What conditions does exploitation require?
What is affected?
Published CVSS scores
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Attacks
What attackers are doing with it
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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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