Cyber Posture

CVE-2025-26565

High

Published: 26 March 2025

Published
26 March 2025
Modified
23 April 2026
KEV Added
Patch
CVSS Score 7.1 CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:L
EPSS Score 0.0011 29.3th percentile
Risk Priority 14 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2025-26565 is a high-severity Cross-site Scripting (CWE-79) vulnerability. Its CVSS base score is 7.1 (High).

Operationally, exploitation aligns with the MITRE ATT&CK technique Malicious Link (T1204.001); ranked at the 29.3th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.

The strongest mitigations our analysis identified are NIST 800-53 SI-10 (Information Input Validation) and SI-15 (Information Output Filtering).

Threat & Defense at a Glance

What attackers do: exploitation maps to Malicious Link (T1204.001) and 3 other techniques. What defenders deploy: see the NIST 800-53 controls recommended below.
Threat & Defense Details

Mitigating Controls (NIST 800-53 r5)AI

prevent

Directly remediates the specific reflected XSS flaw in GNUPress by identifying, patching, and deploying updates to vulnerable versions <=0.2.9.

prevent

Filters information outputs to neutralize untrusted input during web page generation, preventing reflected XSS script execution in victims' browsers.

prevent

Validates user inputs to reject malicious payloads before processing, blocking the improper neutralization exploited in this GNUPress reflected XSS vulnerability.

MITRE ATT&CK Enterprise TechniquesAI

T1204.001 Malicious Link Execution
An adversary may rely upon a user clicking a malicious link in order to gain execution.
T1059.007 JavaScript Execution
Adversaries may abuse various implementations of JavaScript for execution.
T1185 Browser Session Hijacking Collection
Adversaries may take advantage of security vulnerabilities and inherent functionality in browser software to change content, modify user-behaviors, and intercept information as part of various browser session hijacking techniques.
T1539 Steal Web Session Cookie Credential Access
An adversary may steal web application or service session cookies and use them to gain access to web applications or Internet services as an authenticated user without needing credentials.
Why these techniques?

Reflected XSS in public-facing plugin enables arbitrary JavaScript execution via malicious links (T1204.001, T1059.007), directly facilitating browser session hijacking (T1185) and web session cookie theft (T1539) as described.

Confidence: HIGH · MITRE ATT&CK Enterprise v19.0

NVD Description

Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') vulnerability in kagla GNUPress gnupress allows Reflected XSS.This issue affects GNUPress: from n/a through <= 0.2.9.

Deeper analysisAI

CVE-2025-26565 is an Improper Neutralization of Input During Web Page Generation vulnerability, classified as Reflected Cross-site Scripting (XSS) under CWE-79, affecting the GNUPress WordPress plugin developed by kagla. The issue impacts all versions of GNUPress from its initial release through 0.2.9, as disclosed on March 26, 2025.

Unauthenticated attackers can exploit this vulnerability remotely over the network with low attack complexity, requiring user interaction such as clicking a malicious link. The CVSS v3.1 base score of 7.1 (AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:L) reflects a high severity due to the changed scope, enabling script execution in the victim's browser context with low impacts on confidentiality, integrity, and availability, such as session hijacking or data theft.

The Patchstack advisory provides details on this vulnerability in the GNUPress WordPress plugin version 0.2.9 at https://patchstack.com/database/Wordpress/Plugin/gnupress/vulnerability/wordpress-gnupress-plugin-0-2-9-reflected-cross-site-scripting-xss-vulnerability?_s_id=cve.

Details

CWE(s)

CVEs Like This One

CVE-2026-32528Shared CWE-79
CVE-2025-26991Shared CWE-79
CVE-2026-33135Shared CWE-79
CVE-2026-28127Shared CWE-79
CVE-2026-23525Shared CWE-79
CVE-2025-12551Shared CWE-79
CVE-2025-24629Shared CWE-79
CVE-2025-26874Shared CWE-79
CVE-2025-55289Shared CWE-79
CVE-2026-28756Shared CWE-79

References