Cyber Resilience

CVE-2026-34000

Memory Safety in Redhat Enterprise Linux 10.0 … 9.0

Published
05 May 2026
Modified
17 June 2026
CVSS Score v3.1 6.1
Click a component to see what it means
Raw vectorCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:L
EPSS Score 0.0049 40th percentile
Risk Priority 47 floored blend · peak EPSS

Summary

CVE-2026-34000 is a medium-severity Out-of-bounds Read (CWE-125) vulnerability in Redhat Enterprise Linux. Its CVSS base score is 6.1 (Medium).

Operationally, exploitation aligns with the MITRE ATT&CK technique Exploitation for Privilege Escalation (T1068); ranked at the 40th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.

The strongest mitigations our analysis identified map to SA-11 (Developer Testing and Evaluation) and SA-8 (Security and Privacy Engineering Principles) — see the control section below for these in your framework.

EU & UK References

Vulnerability Data

A flaw was found in the X.Org X server. This out-of-bounds read vulnerability in the XKB geometry processing, specifically within the `CheckSetGeom()` and `XkbAddGeomKeyAlias` functions, allows an attacker to read uninitialized or out-of-bounds memory. An attacker with a connection to…

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the X11 server, either locally or remotely, can exploit this without user interaction. This could lead to the disclosure of memory contents or cause a denial of service by crashing the server.

CWE(s)

Related Threats

MITRE ATT&CK Enterprise Techniques

T1068 Exploitation for Privilege Escalation Privilege Escalation
Adversaries may exploit software vulnerabilities in an attempt to elevate privileges.
T1190 Exploit Public-Facing Application Initial Access
Adversaries may attempt to exploit a weakness in an Internet-facing host or system to initially access a network.
T1203 Exploitation for Client Execution Execution
Adversaries may exploit software vulnerabilities in client applications to execute code.
T1210 Exploitation of Remote Services Lateral Movement
Adversaries may exploit remote services to gain unauthorized access to internal systems once inside of a network.
T1211 Exploitation for Stealth Stealth
Adversaries may exploit vulnerabilities to evade detection by hiding activity, suppressing logging, or operating within trusted or unmonitored components.
T1212 Exploitation for Credential Access Credential Access
Adversaries may exploit software vulnerabilities in an attempt to collect credentials.
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2026-50262Same product: Redhat Enterprise Linux
CVE-2026-34002Same product: Redhat Enterprise Linux
CVE-2023-5574Same product: Redhat Enterprise Linux
CVE-2023-6121Same product: Redhat Enterprise Linux
CVE-2026-50264Same product: Redhat Enterprise Linux
CVE-2026-50261Same product: Redhat Enterprise Linux
CVE-2026-50260Same product: Redhat Enterprise Linux
CVE-2026-50263Same product: Redhat Enterprise Linux
CVE-2026-50259Same product: Redhat Enterprise Linux
CVE-2026-50256Same product: Redhat Enterprise Linux

Affected Assets

x.org
x server
all versions
redhat
enterprise linux
10.0, 6.0, 7.0, 8.0, 9.0

Mitigating Controls

Mitigating Controls (NIST 800-53 r5) AI

Developer testing and evaluation directly finds out-of-bounds read flaws through static analysis, fuzzing, and dynamic bounds checks.

Secure engineering principles require bounds checking and memory-safe constructs that stop out-of-bounds reads from being introduced.

Process isolation confines the effects of an out-of-bounds read to the compromised process.

Input validation rejects malformed indices or lengths that would otherwise cause reads outside buffer bounds.

Mitigating Controls (NIST CSF 2.0) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.

PR.PS-06 mostly match
prevents

Secure-development practices such as bounds checking and memory-safe languages directly prevent out-of-bounds reads.

ID.RA-01 partial match
prevents

Vulnerability scanning and recording can discover instances of out-of-bounds reads after code is deployed.

PR.PS-02 partial match
prevents

Routine patching replaces vulnerable code containing out-of-bounds read flaws.

Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.

finds

Security testing in development and acceptance includes fuzzing and static analysis that detect out-of-bounds read defects before release.

A.8.15 Logging partial match
finds

Logging can record evidence of an out-of-bounds read but does not prevent the weakness itself.

prevents

Secure development life cycle mandates input validation and bounds checking that directly prevent out-of-bounds reads.

prevents

Application security requirements include explicit bounds and memory-safety specifications that mitigate buffer over-reads.

prevents

Secure system architecture and engineering principles require memory-safe design patterns and runtime protections against out-of-bounds access.

prevents

Secure coding standards explicitly forbid unsafe pointer arithmetic and mandate bounds-checked reads, eliminating CWE-125.

References