CVE-2026-54025
LibreChat: Stored XSS via unescaped image alt text in markdown artifact preview
- Published
- Updated
- Reserved
- Assigned by
- GitHub_M
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.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| GitHub_MCNA (assigner) | 3.1 | Medium5.4 | CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N |
| NVDNVD · Analyzed | 3.1 | Medium5.4 | CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N |
- EPSS (exploitation in 30 days)
- 0.24% · top 85% of all CVEs (6 Nov 2026)
- CISA SSVC
- Exploitation: poc · Automatable: no · Technical impact: partial
The list uses the assigner's score when there is one, then CISA's, then NVD's: Medium 5.4.
Weakness
Affected products
- affected < 0.8.4-rc1
References (1)
- https://github.com/danny-avila/LibreChat/security/advisories/GHSA-3phr-62qf-cxf3 (opens in a new tab)x_refsource_CONFIRMexploit
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisories (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://trackcve.app/cve/CVE-2026-54025)Record last updated .