Kernel crash via late feature-count initialization
Published Aug 28, 2026 · Updated Aug 28, 2026
Denial of service in Linux 6.15 allows local users to trigger a kernel fortify assertion through the CXL fwctl interface. cxlctl_get_supported_features() copies feature entries while the __counted_by_le(num_entries) bound still reports zero, so Fortify treats the valid write as an overflow. Reaching the path requires a CXL device and local access to issue a Get Supported Features FWCTL_RPC request; the assertion can oops or panic the kernel.
Summary
What happened
Denial of service in Linux 6.15 allows local users to trigger a kernel fortify assertion through the CXL fwctl interface. cxlctl_get_supported_features() copies feature entries while the __counted_by_le(num_entries) bound still reports zero, so Fortify treats the valid write as an overflow. Reaching the path requires a CXL device and local access to issue a Get Supported Features FWCTL_RPC request; the assertion can oops or panic the kernel.
The record
- CVE
- CVE-2026-80640
- Published
- Aug 28, 2026
- Updated
- Aug 28, 2026
- Vendor
- The Linux Kernel Organization
- Product
- Linux
- Classifications
- T1499.004
- Attack vector
- local
- Privileges
- Unavailable
Timeline
How it unfolded
- Aug 28, 2026CVE publishedPublication date reported by the CVE source.
- Aug 28, 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=4d1c09cef2c244bd19467c016a3e56ba28ecc59d <18c67ecc5dafe14055edcea53f36f4e31df1816b
- Affected versionversion=4d1c09cef2c244bd19467c016a3e56ba28ecc59d <6c9d2e87df40d606f1c85143e9acb1ecff463d5e
- Affected versionversion=4d1c09cef2c244bd19467c016a3e56ba28ecc59d <b8d15e85596ad8993d42e0703a9741961a2f03eb
- Affected versionversion=6.15
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What is affected?
Published CVSS scores
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Attacks
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Weakness, pattern, technique
Public exploit references
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Technologies
Your stack
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Your stack
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