CVE-2026-54025

NVD 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.

What to do

• NVD lists no fixed version yet: follow the vendor advisory below and keep LibreChat off the public internet until a fix ships.
• Do not expose the component's API or UI to the internet without authentication in front of it.

Sources

• NVD: CVE-2026-54025
• https://github.com/danny-avila/LibreChat/security/advisories/GHSA-3phr-62qf-cxf3Exploit · Mitigation · Vendor Advisory

Other LibreChat CVEs

All LibreChat CVEs