Kernel memory disclosure via zero-length buffer import
Published May 1, 2026 · Updated May 1, 2026
Out-of-bounds read in io_uring in Linux Kernel 6.15 allows local users to disclose kernel memory or crash the system via a fixed write. validate_fixed_range() accepts a zero-length buffer at the registered region's endpoint, so io_import_fixed() skips past the final bio_vec and reads bv_offset from adjacent slab memory. An unprivileged local user can trigger the deterministic path through io_uring fixed-buffer READ_FIXED or WRITE_FIXED operations when unprivileged io_uring is enabled.
Summary
What happened
Out-of-bounds read in io_uring in Linux Kernel 6.15 allows local users to disclose kernel memory or crash the system via a fixed write. validate_fixed_range() accepts a zero-length buffer at the registered region's endpoint, so io_import_fixed() skips past the final bio_vec and reads bv_offset from adjacent slab memory. An unprivileged local user can trigger the deterministic path through io_uring fixed-buffer READ_FIXED or WRITE_FIXED operations when unprivileged io_uring is enabled.
The record
- CVE
- CVE-2026-43006
- Published
- May 1, 2026
- Updated
- May 1, 2026
- Vendor
- The Linux Kernel Organization
- Product
- Linux Kernel
- Classifications
- CWE-125
- Attack vector
- local
- Privileges
- authenticated
Timeline
How it unfolded
- May 1, 2026CVE publishedPublication date reported by the CVE source.
- May 1, 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?
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- Affected versionversion=6.15
- Affected versionversion=8622b20f23ed165f48b8ca61503a107d17f8d585 <040a1e7e0e2f01851fec1dd2d96906f8636a9f75
- Affected versionversion=8622b20f23ed165f48b8ca61503a107d17f8d585 <111a12b422a8cfa93deabaef26fec48237163214
- Affected versionversion=8622b20f23ed165f48b8ca61503a107d17f8d585 <40170fc1a79c1b2e68f09ae6aac687b7305ae6f4
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What is affected?
Published CVSS scores
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Attacks
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Technologies
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Your stack
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