CVE-2026-54025 Details
Description
LibreChat is an enhanced ChatGPT clone that supports multiple AI providers. Prior to 0.8.4-rc1, there is a vulnerability in LibreChat's markdown artifact preview pipeline. The marked library v15.0.12 does not HTML-escape double-quote characters in image alt text when a custom renderer falls through to the default renderer. LibreChat's generateMarkdownHtml function (in client/src/utils/markdown.ts) installs a custom image renderer that returns false for URLs passing the isSafeUrl allowlist check, which causes marked to fall back to its built-in renderer. That built-in renderer inserts the raw alt text into the alt="..." attribute without escaping double-quote characters. An attacker can craft an alt text such as " onload="payload to break out of the attribute and inject an arbitrary event handler. The resulting HTML is then assigned to document.getElementById('content').innerHTML inside the Sandpack preview iframe, causing the payload to execute in the victim's browser. This vulnerability is fixed in 0.8.4-rc1.
A stored cross-site scripting vulnerability has been identified in LibreChat versions prior to 0.8.4-rc1. The issue arises in the application's markdown artifact preview pipeline, where the 'marked' library version 15.0.12 fails to properly HTML-escape double-quote characters in image alt text. This occurs when a custom image renderer, designed to filter unsafe URLs, defaults to the built-in renderer that does not escape quotes. An attacker can exploit this by crafting alt text that breaks out of the attribute and injects an event handler, executing a payload in the victim's browser. The vulnerability can be exploited by any authenticated user who imports a conversation containing the malicious markdown and shares it publicly, redirecting viewers to an attacker-controlled site.
Users can update to LibreChat version 0.8.4-rc1 or later, where this vulnerability has been fixed.
Metrics
CVSS 4.0 Severity and Vector Strings:
No CVSS 4.0 data is available for this CVE.
CVSS 3.x Severity and Vector Strings:
No data available for CVSS Version 2.0 on this CVE.
CISA-ADP
Assessed Jun 25, 2026References to Advisories, Solutions, and Tools
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| URL | Source(s) | Tag(s) |
|---|---|---|
| https://github.com/danny-avila/LibreChat/security/advisories/GHSA-3phr-62qf-cxf3 | CISA-ADP | ExploitMitigationVendor Advisory |
| https://github.com/danny-avila/LibreChat/security/advisories/GHSA-3phr-62qf-cxf3 | [email protected] | ExploitMitigationVendor Advisory |
Weakness Enumeration
| CWE-ID | CWE Name | Source |
|---|---|---|
| CWE-79 | Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') | [email protected] |
Affected Products
| Product | Versions |
|---|---|
| librechat librechat | <= 0.7.8 |
CPE
Remediation
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Change History
3 change records found show changes
| Date | Action | Recorded By |
|---|---|---|
| Jun 29, 2026 | Initial Analysis | [email protected] |
| Jun 25, 2026 | CVE Modified | CISA-ADP |
| Jun 25, 2026 | New CVE Received | [email protected] |