CVE-2025-62255: Liferay DXP Self-XSS Vulnerability

CVE-2025-62255 Overview

CVE-2025-62255 is a self cross-site scripting (XSS) vulnerability affecting the edit Knowledge Base article page in Liferay Portal and Liferay Digital Experience Platform (DXP). An authenticated attacker can inject arbitrary web script or HTML by crafting a malicious payload inside an attachment filename [CWE-79]. The flaw impacts Liferay Portal versions 7.4.0 through 7.4.3.101, older unsupported versions, and Liferay DXP 2023.Q3.1 through 2023.Q3.5, 7.4 GA through update 92, plus older unsupported releases. Because exploitation is self-targeted, the attacker generally must trick a victim into loading the crafted content in their own session for impact to occur.

Critical Impact
Successful exploitation permits execution of attacker-controlled script in the browser context of the affected Liferay user, enabling limited confidentiality and integrity loss within that session.

Affected Products

Liferay Portal 7.4.0 through 7.4.3.101 (and older unsupported versions)
Liferay DXP 2023.Q3.1 through 2023.Q3.5
Liferay DXP 7.4 GA through update 92 (and older unsupported versions)

Discovery Timeline

2025-10-23 - CVE-2025-62255 published to NVD
2026-06-17 - Last updated in NVD database

Technical Details for CVE-2025-62255

Vulnerability Analysis

The issue is a stored-context self-XSS on the Knowledge Base article edit page. Liferay renders attachment filenames without sufficient output encoding when the edit view lists attached files. An attacker who uploads a file with a crafted filename containing HTML or JavaScript can cause that markup to execute when the edit page is loaded. Exploitation requires low privileges (the attacker must be authenticated with permission to edit Knowledge Base content) and user interaction, which limits real-world impact. The behavior maps to the Cross-Site Scripting weakness class [CWE-79].

Root Cause

The root cause is improper neutralization of user-controlled input during web page generation. The filename metadata is echoed into the rendered HTML of the edit Knowledge Base article page without being HTML-encoded. Because filenames are typically treated as benign metadata, developer-side escaping was omitted for this rendering path.

Attack Vector

The attack path requires an authenticated user session and interaction from a target user. An attacker uploads an attachment whose filename embeds an HTML or JavaScript payload. When a user opens the affected edit Knowledge Base article page and the attachment list renders, the browser parses the injected markup and executes attacker script within the site's origin. The scope of impact is limited to the loading user's browser session, consistent with a self-XSS pattern.

No verified public proof-of-concept code is available. Refer to the Liferay Security Advisory CVE-2025-62255 for vendor-provided details.

Detection Methods for CVE-2025-62255

Indicators of Compromise

Uploaded attachments whose filenames contain HTML tags, angle brackets, or script fragments such as <script>, onerror=, or javascript:.
Content Security Policy (CSP) violation reports originating from Knowledge Base edit views.
Web application access logs showing multipart uploads to Knowledge Base endpoints with unusually long or malformed filename= parameters.

Detection Strategies

Inspect the Liferay Document Library records associated with Knowledge Base attachments for filenames that contain HTML metacharacters.
Deploy a WAF rule to flag file upload requests to Knowledge Base APIs where the filename field contains <, >, or " characters.
Review audit logs for repeated edits or attachment uploads on Knowledge Base articles by low-privilege authors.

Monitoring Recommendations

Enable and forward Liferay application logs and web server access logs to a centralized analytics platform for correlation.
Configure browser-side CSP with reporting enabled to capture unexpected inline script execution in admin views.
Alert on newly created Knowledge Base attachments whose filename length or character set deviates from the organization's baseline.

How to Mitigate CVE-2025-62255

Immediate Actions Required

Apply the vendor-supplied fix referenced in the Liferay Security Advisory CVE-2025-62255.
Restrict Knowledge Base authoring permissions to trusted, named accounts.
Audit existing Knowledge Base attachments and rename or remove any files whose filenames contain HTML or script fragments.

Patch Information

Liferay has published a security advisory for CVE-2025-62255. Upgrade Liferay Portal beyond 7.4.3.101 and Liferay DXP beyond 2023.Q3.5 or 7.4 update 92 per the vendor guidance. Consult the Liferay Security Advisory CVE-2025-62255 for the specific fix pack that addresses the vulnerable rendering path.

Workarounds

Enforce a strict Content Security Policy on Liferay administrative interfaces to block inline script execution.
Enable server-side filename validation that rejects uploads whose filenames include HTML metacharacters such as <, >, ", or '.
Provide security awareness training so Knowledge Base editors avoid opening attachments from untrusted contributors while a patch is pending.

bash

# Configuration example: sample nginx rule to reject multipart uploads whose
# filename parameter contains HTML metacharacters (defense-in-depth only).
if ($request_body ~* "filename=\"[^\"]*[<>\"'][^\"]*\"") {
    return 400;
}