Privilege escalation via undersized XKB action allocation
Published Dec 13, 2023 · Updated Jun 23, 2026
Out-of-bounds access in the X.Org X Server on Red Hat Enterprise Linux allows local users to escalate privileges through XKB button-action requests. A logical device switch recalculates a master pointer's actions but allocates space for only one action instead of every button on the active device. The local path requires a privileged X server; a forwarded X11 session exposes remote code execution.
Summary
What happened
Out-of-bounds access in the X.Org X Server on Red Hat Enterprise Linux allows local users to escalate privileges through XKB button-action requests. A logical device switch recalculates a master pointer's actions but allocates space for only one action instead of every button on the active device. The local path requires a privileged X server; a forwarded X11 session exposes remote code execution.
The record
- CVE
- CVE-2023-6377
- Published
- Dec 13, 2023
- Updated
- Jun 23, 2026
- Vendor
- Red Hat
- Product
- Red Hat Enterprise Linux 8.4 Advanced Mission Critical Update Support
- Classifications
- CWE-125, T1068
- Attack vector
- local
- Privileges
- authenticated
Timeline
How it unfolded
- Dec 13, 2023CVE publishedPublication date reported by the CVE source.
- Jun 23, 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?
Affected versions are unavailable in this record. Check the vendor advisory for version and patch details.
What conditions does exploitation require?
What is affected?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
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Public exploit references
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Technologies
Your stack
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Your stack
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