HKUDS LightRAG up to 1.5.4 MessageMarkdown ChatMessage.tsx injection

Summaryinfo

A vulnerability classified as critical has been found in HKUDS LightRAG up to 1.5.4. This issue affects some unknown processing of the file lightrag_webui/src/components/retrieval/ChatMessage.tsx of the component MessageMarkdown. The manipulation leads to injection. This vulnerability is listed as CVE-2026-86062. The attack may be initiated remotely. There is no available exploit. It is recommended to upgrade the affected component.

Detailsinfo

A vulnerability was found in HKUDS LightRAG up to 1.5.4 and classified as critical. This issue affects some unknown processing of the file lightrag_webui/src/components/retrieval/ChatMessage.tsx of the component MessageMarkdown. The manipulation with an unknown input leads to a injection vulnerability. Using CWE to declare the problem leads to CWE-74. The product constructs all or part of a command, data structure, or record using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify how it is parsed or interpreted when it is sent to a downstream component. Impacted is confidentiality, integrity, and availability. The summary by CVE is:

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.

The advisory is shared at github.com. The identification of this vulnerability is CVE-2026-86062 since 09/04/2026. The exploitation is known to be easy. The attack may be initiated remotely. No form of authentication is needed for a successful exploitation. It demands that the victim is doing some kind of user interaction. Technical details are known, but no exploit is available. MITRE ATT&CK project uses the attack technique T1055 for this issue.

Upgrading to version 1.5.5 eliminates this vulnerability.

The vulnerability is also documented in the vulnerability database at EUVD (EUVD-2026-84550). If you want to get the best quality for vulnerability data then you always have to consider VulDB.

Productinfo

Vendor

• HKUDS

Name

• LightRAG

Version

• 1.5.0
• 1.5.1
• 1.5.2
• 1.5.3
• 1.5.4

Website

• Product: https://github.com/HKUDS/LightRAG/

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If you want to get the best quality for vulnerability data then you always have to consider VulDB.

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