Kernel crash via unchecked UCSI altmode index
Published Sep 16, 2026 · Updated Sep 16, 2026
Out-of-bounds array access in the Linux kernel allows attackers able to influence a UCSI PPM response to crash the system. The UCSI DisplayPort entry path uses GET_CURRENT_CAM as an index into the fixed-length port_altmode array after excluding only 0xff, without enforcing UCSI_MAX_ALTMODES. Reachability requires a UCSI DisplayPort path and a PPM that returns another out-of-range value; the documented consequence is a kernel crash.
Summary
What happened
Out-of-bounds array access in the Linux kernel allows attackers able to influence a UCSI PPM response to crash the system. The UCSI DisplayPort entry path uses GET_CURRENT_CAM as an index into the fixed-length port_altmode array after excluding only 0xff, without enforcing UCSI_MAX_ALTMODES. Reachability requires a UCSI DisplayPort path and a PPM that returns another out-of-range value; the documented consequence is a kernel crash.
The record
- CVE
- CVE-2026-90025
- Published
- Sep 16, 2026
- Updated
- Sep 16, 2026
- Vendor
- The Linux Kernel Organization
- Product
- Linux
- Classifications
- T1499
- Attack vector
- Unavailable
- Privileges
- Unavailable
Timeline
How it unfolded
- Sep 16, 2026CVE publishedPublication date reported by the CVE source.
- Sep 16, 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=5.2
- Affected versionversion=af8622f6a585d8d82b11cd7987e082861fd0edd3 <04cec690b1fd9d1c4c314b91a10d8c68a3acfe18
- Affected versionversion=af8622f6a585d8d82b11cd7987e082861fd0edd3 <1ffed96ef986e2cdf986aa4a4506a5e6dcdf4456
- Affected versionversion=af8622f6a585d8d82b11cd7987e082861fd0edd3 <33a81acd2d1d0667d4eff93cb90339fa53e617e8
- Affected versionversion=af8622f6a585d8d82b11cd7987e082861fd0edd3 <58e0ee293ec5e06cacbe3953ad44042f1473dae9
- Affected versionversion=af8622f6a585d8d82b11cd7987e082861fd0edd3 <83f1abd62cc134700ba92e1e2dc650a49a185497
- Affected versionversion=af8622f6a585d8d82b11cd7987e082861fd0edd3 <8fde7e4a366184e9a6aa95541e52933a73c00a74
- Affected versionversion=af8622f6a585d8d82b11cd7987e082861fd0edd3 <ac9f878c468052af6571e8639ab1c3ae040b908f
- Affected versionversion=af8622f6a585d8d82b11cd7987e082861fd0edd3 <bdaaf3074aedce8f1b173cc363d61cff5f6a585f
What conditions does exploitation require?
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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