Cyber Resilience

CVE-2025-26599

Memory Safety in Redhat Enterprise Linux 7.0 … 9.0

Published
25 February 2025
Modified
29 June 2026
CVSS Score v3.1 7.8
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:H/A:H
EPSS Score 0.0040 33th percentile
Risk Priority 57 floored blend · peak EPSS

Summary

CVE-2025-26599 is a high-severity Access of Uninitialized Pointer (CWE-824) vulnerability in Redhat Enterprise Linux. Its CVSS base score is 7.8 (High).

Operationally, exploitation aligns with the MITRE ATT&CK technique Exploitation for Privilege Escalation (T1068); ranked at the 33th 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-15 (Development Process, Standards, and Tools) — see the control section below for these in your framework.

Deeper analysis AI-assisted summary

Synthesised by an AI model from the NVD description and linked references — a reading aid, not an authoritative source.

CVE-2025-26599 is an access to an uninitialized pointer flaw (CWE-824) affecting X.Org and Xwayland. The vulnerability arises when the function compCheckRedirect() fails to allocate the backing pixmap, causing compRedirectWindow() to return a BadAlloc error without fully validating the previously marked window tree. This leaves the validated data partly uninitialized, resulting in the subsequent use of an uninitialized pointer. The issue was published on 2025-02-25 and carries a CVSS v3.1 base score of 7.8 (AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H).

A local attacker with low privileges can exploit this vulnerability with low complexity and no user interaction required. Successful exploitation grants high-impact access to confidential data, modification of system integrity, and disruption of availability, potentially leading to full system compromise on affected X.Org or Xwayland installations.

Red Hat has released multiple errata addressing the flaw, including RHSA-2025:2500, RHSA-2025:2502, RHSA-2025:2861, RHSA-2025:2862, and RHSA-2025:2865, which provide updated packages with fixes for vulnerable systems.

EU & UK References

Vulnerability Data

An access to an uninitialized pointer flaw was found in X.Org and Xwayland. The function compCheckRedirect() may fail if it cannot allocate the backing pixmap. In that case, compRedirectWindow() will return a BadAlloc error without validating the window tree marked…

more

just before, which leaves the validated data partly initialized and the use of an uninitialized pointer later.

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-2025-26595Same product: Redhat Enterprise Linux
CVE-2025-26598Same product: Redhat Enterprise Linux
CVE-2025-26596Same product: Redhat Enterprise Linux
CVE-2025-26594Same product: Redhat Enterprise Linux
CVE-2025-26600Same product: Redhat Enterprise Linux
CVE-2025-26601Same product: Redhat Enterprise Linux
CVE-2025-26597Same product: Redhat Enterprise Linux
CVE-2026-50264Same product: Redhat Enterprise Linux
CVE-2026-50262Same product: Redhat Enterprise Linux
CVE-2023-6377Same product: Redhat Enterprise Linux

Affected Assets

tigervnc
tigervnc
all versions
x.org
x server
≤ 21.1.16
x.org
xwayland
≤ 24.1.6
redhat
enterprise linux
7.0, 8.0, 9.0

Mitigating Controls

Mitigating Controls (NIST 800-53 r5) AI

Developer testing and evaluation can discover uninitialized pointer accesses through static analysis, dynamic testing, or fuzzing before deployment.

Requiring documented development processes and tools enables use of analyzers or coding standards that identify uninitialized pointer defects.

Security engineering principles can mandate memory-safety practices and language choices that structurally avoid uninitialized pointer use.

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 SDLC practices directly prevent uninitialized pointer bugs via coding standards, analysis, and reviews, but eliminating this single weakness only partially fulfills the broader control.

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 can detect uninitialized pointer usage before release.

prevents

Secure development life cycle mandates practices that reduce uninitialized pointer defects.

degrades

Application security requirements can specify pointer initialization rules.

degrades

Secure architecture principles discourage unsafe pointer handling.

prevents

Secure coding standards directly prohibit use of uninitialized pointers.

References