Local privilege escalation via unchecked XKB request lengths
Published Apr 23, 2026 · Updated Apr 23, 2026
Out-of-bounds access in X.Org Server and Xwayland on Red Hat Enterprise Linux releases allows local users to expose memory or crash the server. CheckKeyTypes iterates over key-type elements derived from an XKB client request without sufficient bounds checks, so later reads pass the request payload. A low-privileged local X client can disclose adjacent memory or terminate the display server; arbitrary code execution is configuration-dependent.
Summary
What happened
Out-of-bounds access in X.Org Server and Xwayland on Red Hat Enterprise Linux releases allows local users to expose memory or crash the server. CheckKeyTypes iterates over key-type elements derived from an XKB client request without sufficient bounds checks, so later reads pass the request payload. A low-privileged local X client can disclose adjacent memory or terminate the display server; arbitrary code execution is configuration-dependent.
The record
- CVE
- CVE-2026-34003
- Published
- Apr 23, 2026
- Updated
- Apr 23, 2026
- Vendor
- 389 Directory Server
- Product
- Red Hat Enterprise Linux 6
- Classifications
- CWE-125, T1068
- Attack vector
- local
- Privileges
- authenticated
Timeline
How it unfolded
- Apr 23, 2026CVE publishedPublication date reported by the CVE source.
- Apr 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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