CVE-2026-34000
Out-of-Bounds Read in X.Org X Server
Publication date: 2026-05-05
Last updated on: 2026-05-05
Assigner: Red Hat, Inc.
Description
Description
CVSS Scores
EPSS Scores
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Meta Information
Affected Vendors & Products
| Vendor | Product | Version / Range |
|---|---|---|
| x.org | x_server | * |
Helpful Resources
Exploitability
| CWE ID | Description |
|---|---|
| CWE-125 | The product reads data past the end, or before the beginning, of the intended buffer. |
Attack-Flow Graph
AI Powered Q&A
How does this vulnerability affect compliance with common standards and regulations (like GDPR, HIPAA)?:
This vulnerability allows an attacker to read uninitialized or out-of-bounds memory, potentially leading to the disclosure of sensitive memory contents. Such unauthorized disclosure of information could impact compliance with data protection regulations like GDPR and HIPAA, which require safeguarding personal and sensitive data against unauthorized access.
However, the provided information does not explicitly discuss compliance implications or specific impacts on regulatory standards.
What immediate steps should I take to mitigate this vulnerability?
To mitigate this vulnerability, it is important to restrict access to the X.Org X server, as the flaw can be exploited by attackers with local or remote access to the X11 server.
- Limit or disable remote forwarded X11 sessions to prevent remote exploitation.
- Apply any available patches or updates from your vendor addressing this specific vulnerability.
- Consider restarting the X server after applying patches to ensure the fix is active.
These steps help reduce the risk of information disclosure or denial of service caused by this out-of-bounds read vulnerability.
Can you explain this vulnerability to me?
CVE-2026-34000 is an out-of-bounds read vulnerability in the X.Org X server's XKB geometry processing. It specifically affects the CheckSetGeom() and XkbAddGeomKeyAlias functions. The flaw occurs because bounds checking only validates the first key name of each alias entry, leaving the second name unchecked. This allows an attacker to read uninitialized or out-of-bounds memory when processing a specially crafted request.
An attacker with access to the X11 server, either locally or remotely through forwarded sessions, can exploit this vulnerability without any user interaction.
How can this vulnerability impact me? :
Exploitation of this vulnerability can lead to the disclosure of sensitive memory contents, potentially exposing confidential information.
Additionally, it can cause a denial-of-service condition by crashing the X.Org X server, disrupting normal system operations.