Kernel crash via undersized Thunderbolt property directory
Published Jul 19, 2026 · Updated Jul 19, 2026
Out-of-bounds reads in the Linux Kernel Thunderbolt property parser allow attackers to crash the kernel via a crafted property directory. On the non-root path, __tb_property_parse_dir() copies four UUID dwords before validating that entry->length is at least four, then subtracts four into size_t and walks an enormous entry count after underflow. Reachability requires a directory entry whose length is zero through three; the established consequence is a kernel oops and service interruption, not demonstrated data disclosure.
Summary
What happened
Out-of-bounds reads in the Linux Kernel Thunderbolt property parser allow attackers to crash the kernel via a crafted property directory. On the non-root path, __tb_property_parse_dir() copies four UUID dwords before validating that entry->length is at least four, then subtracts four into size_t and walks an enormous entry count after underflow. Reachability requires a directory entry whose length is zero through three; the established consequence is a kernel oops and service interruption, not demonstrated data disclosure.
The record
- CVE
- CVE-2026-63892
- Published
- Jul 19, 2026
- Updated
- Jul 19, 2026
- Vendor
- The Linux Kernel Organization
- Product
- Linux Kernel
- Classifications
- T1499.004
- Attack vector
- Unavailable
- Privileges
- Unavailable
Timeline
How it unfolded
- Jul 19, 2026CVE publishedPublication date reported by the CVE source.
- Jul 19, 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=4.15
- Affected versionversion=cdae7c07e3e3509eaabc18c1640a55dc5b99c179 <37abc4504fa19d8f9f1e87792e8a2b8fdb308e40
- Affected versionversion=cdae7c07e3e3509eaabc18c1640a55dc5b99c179 <3bec49ca55e08fb085cc4318f24b1b37eaab28cb
- Affected versionversion=cdae7c07e3e3509eaabc18c1640a55dc5b99c179 <542a13890b742099c461d70920e97b14e568f6ec
- Affected versionversion=cdae7c07e3e3509eaabc18c1640a55dc5b99c179 <5506c825f14d810f0690b1f4367cb7249ebb387a
- Affected versionversion=cdae7c07e3e3509eaabc18c1640a55dc5b99c179 <d548179adcc87e1bc66b17e00352a1f536e76065
- Affected versionversion=cdae7c07e3e3509eaabc18c1640a55dc5b99c179 <de21b59c29e31c5108ddc04210631bbfab81b997
- Affected versionversion=cdae7c07e3e3509eaabc18c1640a55dc5b99c179 <de618299190b418291609e6921557253bd417e25
- Affected versionversion=cdae7c07e3e3509eaabc18c1640a55dc5b99c179 <e2d4d51cf5785815fa4e91e0c019e3eb2506a84c
What conditions does exploitation require?
What is affected?
Published CVSS scores
No CVSS assessment is available in this record.
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Attacks
What attackers are doing with it
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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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