External risk intelligence

XWiki Rendering Script Macro Injection Vulnerability

CVE advisorySeverity: CRITICAL (CVSS 9.9)

CVE-2025-53837

XWiki is a web-based collaborative platform commonly deployed as a public-facing or organization-wide web application. While the vulnerability requires authenticated access to edit documents, the application itself is typically exposed to the internet or wide internal networks to facilitate user collaboration, making the interface reachable in common deployment patterns.

Remote Code Execution

Halo Surface Signal: 4 out of 5 — likely to be public-facing.

External exposure likelihood

Horizon Alert

Summary of the vulnerability and why it matters

This advisory concerns a critical vulnerability in the XWiki Rendering system, which processes various text formats. The flaw allows authenticated users to execute arbitrary scripts, potentially leading to remote code execution and unrestricted access to wiki content. The issue arises from improper handling of rendered output within HTML macros.

Scripts can be run by users editing profiles or documents.
It enables unauthorized access and control of wiki content.
Confirm relevance and review exposure for XWiki Rendering systems.

Attack Path

How an attacker could exploit the issue

A user with the ability to edit documents or their own profile can inject malicious script macros into the wiki. This occurs because the output of the rendering system, which processes various text formats, is included within HTML macros without proper escaping. An attacker can exploit this by closing the HTML macro and inserting script commands, such as Groovy or Python, which can then execute with full programming rights.

Authenticated access to edit content.
Injecting script macros into HTML.
Arbitrary code execution and data access.

Live Threat

Current exploitation, exposure, and threat context

The XWiki Rendering system could allow users with document editing privileges to execute arbitrary scripts, including those with remote code execution capabilities. This could lead to unrestricted read and write access to all wiki content.

Editable wiki content.
Injection via script macros.
Unrestricted wiki content access.

Operational Fix

Recommended remediation, mitigation, and detection steps

Application owners and platform teams are likely responsible for addressing this critical vulnerability in XWiki Rendering. The first practical step is to inventory all XWiki instances, confirm their exposure and business criticality, and identify the accountable owner for each. Remediation planning should then be prioritized based on this risk assessment.

Application owners should lead remediation efforts.
Verify XWiki instance exposure and criticality.
Plan remediation based on identified risks.

Supplementary metadata

CVSS vector

Validate whether this threat affects your internet-facing exposure.

Halo Threat Intelligence helps prioritize remediation with Halo Surface Signal and H/A/L/O context. Start exposure validation with a free external attack surface trial.

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Frequently asked questions

What is XWiki Rendering and how is it used?

XWiki Rendering is the underlying engine in the XWiki platform that translates various input formats—such as raw text or wiki markup—into structured web content like XHTML. It essentially acts as the translator that allows users to write documentation or collaborate on pages while ensuring the output displays correctly for everyone else in the web browser.

What does CWE-95 mean for CVE-2025-53837?

CWE-95 refers to Improper Neutralization of Directives in Dynamically Evaluated Code, commonly known as a code injection flaw. In this case, the rendering system fails to properly escape input before processing it. This allows an attacker to break out of expected HTML boundaries and inject unauthorized script commands, such as Groovy or Python, which the server then executes as if they were legitimate system instructions.

How does an attacker trigger this vulnerability?

An attacker must have existing document editing permissions to trigger this flaw, such as the ability to edit their own user profile or any wiki document. The vulnerability is NOT triggered by simply viewing pages; it requires the active submission of crafted content that forces the rendering system to process malicious script macros instead of plain text.

Is my XWiki instance at risk?

If your XWiki instance is accessible to users, it could be at risk. Halo Surface Signal identifies XWiki as a platform often deployed as a public-facing or wide-reaching internal application. Because the vulnerability allows an authenticated user to gain extensive control, any instance where users have document editing rights is a potential target, regardless of whether the site is hosted on the internet or an internal network.

What should I do to secure my environment?

Begin by inventorying all XWiki instances within your organization to determine which ones are running vulnerable versions. Identify the owners for these systems and prioritize updates to versions 14.10.2 or 15.0 RC1, where the rendering engine has been patched to prevent script injection. If immediate patching is not possible, consult the XWiki documentation for available configuration workarounds.

References

Written by Nicholas Merritt

Nicholas Merritt is VP of Security Solutions at Halo Security. With more than 25 years across application security, vulnerability prioritization, and offensive security, he helps teams translate threat data into practical exposure validation and remediation focus. He authors Halo Threat Intelligence CVE advisories using Halo Surface Signal and H/A/L/O context to prioritize internet-facing risk.