Medium

LightRAG: Stored Cross-Site Scripting (XSS) in the LightRAG WebUI chat/answer renderer via ingested content

Type: advisorySources: OSV

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.

Products: Not specified
Affected versions: Not specified
Fixed versions: Not specified
CVEs: CVE-2026-86062
Confirmed fixed CVEs: Not specified
Updated in this feed: 3 Nov 2026, 02:48 UTC · Revision 1

Source evidence

LightRAG: Stored Cross-Site Scripting (XSS) in the LightRAG WebUI chat/answer renderer via ingested content

core-osv · Original source

Published 22 Sept 2026, 16:21 UTC

osv:CVE-2026-86062

Complete source record

{
  "id": "d459a176aeffbd27f5f0d0a7e8eee0255191adfb1934743bcb0dc254d72303da",
  "url": "https://osv.dev/vulnerability/CVE-2026-86062",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "LightRAG: Stored Cross-Site Scripting (XSS) in the LightRAG WebUI chat/answer renderer via ingested content",
    "summary": "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.",
    "evidence": "osv:CVE-2026-86062",
    "products": [],
    "severity": "medium",
    "structured": {
      "id": "CVE-2026-86062",
      "aliases": [
        "CVE-2026-86062",
        "GHSA-xpjq-3w4w-w5wr",
        "PYSEC-2026-4065"
      ],
      "metrics": [
        {
          "type": "CVSS_V3",
          "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://github.com/hkuds/lightrag",
              "type": "GIT",
              "events": [
                {
                  "introduced": "0"
                },
                {
                  "fixed": "22ea2d0cbfa2b7002aa118bd0bf1780a69d489bc"
                },
                {
                  "fixed": "8bf032a5200f293b482dd945d436e25cd08bd953"
                }
              ],
              "database_specific": {
                "extracted_events": [
                  {
                    "range": [
                      {
                        "introduced": "0"
                      },
                      {
                        "fixed": "1.5.5"
                      }
                    ],
                    "source": "AFFECTED_FIELD",
                    "strategy": "StringRangeExpression"
                  },
                  {
                    "range": [
                      {
                        "fixed": "8bf032a5200f293b482dd945d436e25cd08bd953"
                      }
                    ],
                    "source": "REFERENCES_COMMIT"
                  },
                  {
                    "range": [
                      {
                        "fixed": "22ea2d0cbfa2b7002aa118bd0bf1780a69d489bc"
                      }
                    ],
                    "source": "REFERENCES_TAG",
                    "original_tag": "v1.5.5"
                  }
                ]
              }
            }
          ],
          "versions": [
            "v1.5.5rc1",
            "v1.5.4",
            "temp",
            "v1.5.3",
            "v1.5.2",
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            "v1.4.8rc4",
            "v1.4.8rc3",
            "v1.4.8rc1",
            "v1.4.7",
            "v1.4.7rc2",
            "v1.4.6",
            "v1.4.5",
            "v1.4.4",
            "v1.4.3",
            "v1.4.2",
            "v1.4.1",
            "v1.4.0",
            "v1.3.10",
            "v1.3.9",
            "v1.3.8",
            "v1.3.7",
            "v1.3.6",
            "v1.3.4",
            "v1.3.3",
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            "v1.2.1",
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            "v1.1.10",
            "v1.1.9",
            "v1.1.8",
            "v1.1.7",
            "v1.1.6",
            "v1.1.5",
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            "v1.1.3",
            "v1.1.2",
            "v1.1.1",
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            "v1.0.8",
            "v1.0.7",
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          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-86062.json"
          }
        }
      ],
      "modified": "2026-10-28T02:30:25.491267940Z",
      "provider": "osv",
      "references": [
        "https://github.com/HKUDS/LightRAG/releases/tag/v1.5.5",
        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/86xxx/CVE-2026-86062.json",
        "https://github.com/HKUDS/LightRAG/security/advisories/GHSA-xpjq-3w4w-w5wr",
        "https://nvd.nist.gov/vuln/detail/CVE-2026-86062",
        "https://github.com/HKUDS/LightRAG/commit/8bf032a5200f293b482dd945d436e25cd08bd953",
        "https://github.com/HKUDS/LightRAG/pull/3437"
      ],
      "provider_metadata": {
        "cwe_ids": [
          "CWE-79"
        ],
        "cna_assigner": "GitHub_M",
        "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/86xxx/CVE-2026-86062.json"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2026-86062",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 492027,
  "published_at": "2026-09-22T16:21:43.846+00:00"
}