CVE-2026-86062Public exploitNetwork attack vectorHinoki check available

Stored script execution via unsanitized answer rendering

Published Sep 22, 2026 · Updated Sep 22, 2026

Stored XSS in LightRAG WebUI before 1.5.5 allows remote attackers to run JavaScript when a user retrieves an ingested document. ChatMessage.tsx passes answer and thinking content through react-markdown with rehypeRaw and HTML enabled but without sanitization; its Mermaid path also inserts loose-mode SVG through innerHTML. An attacker must add content and induce later retrieval, after which code runs in the WebUI origin and can read the API token or perform API actions as the victim.

CVSS severity6.1
Medium
EPSS probability0.25%
Next 30 days · Oct 19, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkAvailable
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Summary

What happened

Stored XSS in LightRAG WebUI before 1.5.5 allows remote attackers to run JavaScript when a user retrieves an ingested document. ChatMessage.tsx passes answer and thinking content through react-markdown with rehypeRaw and HTML enabled but without sanitization; its Mermaid path also inserts loose-mode SVG through innerHTML. An attacker must add content and induce later retrieval, after which code runs in the WebUI origin and can read the API token or perform API actions as the victim.

The record

CVE
CVE-2026-86062
Published
Sep 22, 2026
Updated
Sep 22, 2026
Vendor
Data Intelligence Lab @ HKU
Product
LightRAG
Classifications
CWE-79, T1528
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Sep 22, 2026CVE publishedPublication date reported by the CVE source.
  2. Sep 22, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=< 1.5.5

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Data Intelligence Lab @ HKU · LightRAGversion=< 1.5.5

Published CVSS scores

6.1GitHub Security AdvisoryCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Activity data is delayed. The latest report is Sep 28, 2026.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 22, 2026Sep 28, 2026
Latest reporting daySep 28, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-79Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
T1528Steal Application Access Token

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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