Cyber Resilience

CVE-2025-26597

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 0.0043 36th percentile
Risk Priority 57 floored blend · peak EPSS

Summary

CVE-2025-26597 is a high-severity Improper Restriction of Operations within the Bounds of a Memory Buffer (CWE-119) vulnerability in Redhat Enterprise Linux. Its CVSS base score is 7.8 (High).

Operationally, exploitation aligns with the MITRE ATT&CK technique Process Injection (T1055); ranked at the 36th 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-8 (Security and Privacy Engineering Principles) and SI-10 (Information Input Validation) — 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-2025-26597 is a buffer overflow vulnerability in X.Org and Xwayland. The flaw occurs in the XkbChangeTypesOfKey() function: when called with a group value of 0, it resizes the key symbols table to zero while leaving the key actions unchanged. A subsequent call with a non-zero group value then triggers a buffer overflow due to the mismatched size of the key actions table. This issue, classified under CWE-119 (Improper Restriction of Operations within the Bounds of a Memory Buffer), received a CVSS v3.1 base score of 7.8.

The vulnerability can be exploited by a local attacker with low privileges (PR:L). It requires local access (AV:L) and low attack complexity (AC:L) with no user interaction (UI:N), allowing the attacker to achieve high impacts on confidentiality, integrity, and availability (C:H/I:H/A:H) within the affected system's scope (S:U). Successful exploitation could enable arbitrary code execution or system compromise from a low-privileged context.

Red Hat has addressed the vulnerability through multiple errata releases, including RHSA-2025:2500, RHSA-2025:2502, RHSA-2025:2861, RHSA-2025:2862, and RHSA-2025:2865, which provide updated packages for affected X.Org and Xwayland components in various Red Hat Enterprise Linux versions. Security practitioners should apply these patches promptly to mitigate the risk.

EU & UK References

Vulnerability Data

A buffer overflow flaw was found in X.Org and Xwayland. If XkbChangeTypesOfKey() is called with a 0 group, it will resize the key symbols table to 0 but leave the key actions unchanged. If the same function is later called…

more

with a non-zero value of groups, this will cause a buffer overflow because the key actions are of the wrong size.

CWE(s)

Related Threats

MITRE ATT&CK Enterprise Techniques

T1055 Process Injection Stealth
Adversaries may inject code into processes in order to evade process-based defenses as well as possibly elevate privileges.
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.
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-2025-26601Same product: Redhat Enterprise Linux
CVE-2025-26594Same product: Redhat Enterprise Linux
CVE-2025-26600Same product: Redhat Enterprise Linux
CVE-2025-26595Same product: Redhat Enterprise Linux
CVE-2025-26598Same product: Redhat Enterprise Linux
CVE-2025-26599Same product: Redhat Enterprise Linux
CVE-2025-26596Same 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

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

Control response

Prevent
Stop it (NIST 800-53)

Detect
Catch it (NIST detect / respond)

Harden
Shrink the surface (DISA STIG)

Validate
Prove the fix (OWASP ASVS)
  • V17.3.2

Mitigating Controls (NIST 800-53 r5) AI

Secure engineering principles require memory-safe design and coding that structurally avoids buffer-boundary violations.

Input validation directly enforces bounds checking that stops out-of-bounds reads/writes from being introduced or reached.

Memory protection restricts exploitation impact of buffer overflows without eliminating the underlying coding flaw.

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 (bounds checking, safe APIs, reviews) directly prevent this class of flaw.

ID.RA-01 partial match
prevents

Vulnerability scanning and code analysis directly surface buffer-boundary flaws.

ID.RA-08 partial match
prevents

Receiving and triaging vulnerability disclosures commonly includes buffer-related reports.

PR.AT-02 partial match
prevents

Developer training on secure coding reduces introduction of memory-buffer errors.

PR.PS-02 partial match
prevents

Patching replaces vulnerable code containing buffer-boundary defects.

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 catches out-of-bounds accesses before release, covering most instances of the weakness.

prevents

Secure development lifecycle mandates memory-safety practices that directly prevent buffer-boundary violations.

prevents

Application security requirements can specify memory-safety rules, but do not prescribe implementation details.

prevents

Secure architecture and engineering principles include memory-safe design patterns that mitigate buffer overflows.

prevents

Secure coding standards explicitly forbid unsafe buffer operations, directly eliminating CWE-119.

References