Vulnerability · Published Sep 22, 2026 · Assigned by GitHub_M
CVE-2026-86062LightRAG: Stored Cross-Site Scripting (XSS) in the LightRAG WebUI chat/answer renderer via ingested content
Medium 6.1
In plain English
A medium-severity cross-site scripting in LightRAG from HKUDS. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.3% (higher than 27% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Official description
LightRAG provides simple and fast retrieval-augmented generation. Prior to 1.5.5, lightrag_webui/src/components/retrieval/ChatMessage.tsx renders answer and thinking content with react-markdown, rehypeRaw, and skipHtml=false without an HTML sanitizer. An attacker who can add a document can store raw HTML that is returned through the query path and rendered as active content by MessageMarkdown. A user who later retrieves the content can execute attacker-controlled JavaScript through elements such as an iframe srcdoc; the additional Mermaid securityLevel: loose rendering path also injects generated SVG through innerHTML. The script runs in the LightRAG WebUI origin and can read the API token in localStorage and perform API actions as the victim. This issue is fixed in version 1.5.5.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| PyPI | lightrag-hku | 1.5.5 | GHSA-xpjq-3w4w-w5wr |
| PyPI | lightrag-hku | 1.5.5 | PYSEC-2026-4065 |
Affected products (as reported)
Weakness: CWE-79 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
References
- https://github.com/HKUDS/LightRAG/security/advisories/GHSA-xpjq-3w4w-w5wr x_refsource_CONFIRM
- https://github.com/HKUDS/LightRAG/pull/3437 x_refsource_MISC
- https://github.com/HKUDS/LightRAG/commit/8bf032a5200f293b482dd945d436e25cd08bd953 x_refsource_MISC
- https://github.com/HKUDS/LightRAG/releases/tag/v1.5.5 x_refsource_MISC