SiYuan: Reflected XSS via SVG namespace prefix bypass in SanitizeSVG ( getDynamicIcon, unauthenticated )

{
  "id": "0db43ee9f00058b322b4813a4d20f09c15e2b6f0270db56c27339580bd156840",
  "url": "https://osv.dev/vulnerability/CVE-2026-34605",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "SiYuan: Reflected XSS via SVG namespace prefix bypass in SanitizeSVG ( getDynamicIcon, unauthenticated )",
    "summary": "SiYuan is a personal knowledge management system. From version 3.6.0 to before version 3.6.2, the SanitizeSVG function introduced in version 3.6.0 to fix XSS in the unauthenticated /api/icon/getDynamicIcon endpoint can be bypassed by using namespace-prefixed element names such as . The Go HTML5 parser records the element's tag as \"x:script\" rather than \"script\", so the tag check passes it through. The SVG is served with Content-Type: image/svg+xml and no Content Security Policy; when a browser opens the response directly, its XML parser resolves the prefix to the SVG namespace and executes the embedded script. This issue has been patched in version 3.6.2.",
    "evidence": "osv:CVE-2026-34605",
    "products": [],
    "severity": "high",
    "structured": {
      "id": "CVE-2026-34605",
      "aliases": [
        "CVE-2026-34605",
        "GHSA-73g7-86qr-jrg3",
        "GO-2026-5201"
      ],
      "metrics": [
        {
          "type": "CVSS_V4",
          "score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:H/VI:H/VA:L/SC:N/SI:N/SA:N"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://github.com/siyuan-note/siyuan",
              "type": "GIT",
              "events": [
                {
                  "introduced": "fd6526133bb318d534b8865998f8059ae765fdd1"
                },
                {
                  "fixed": "29b104f338f9b0cdda0df852871a09a6268ced2f"
                }
              ],
              "database_specific": {
                "extracted_events": [
                  {
                    "range": [
                      {
                        "introduced": "3.6.0"
                      },
                      {
                        "fixed": "3.6.2"
                      }
                    ],
                    "source": "AFFECTED_FIELD",
                    "strategy": "StringRangeExpression"
                  },
                  {
                    "range": [
                      {
                        "fixed": "29b104f338f9b0cdda0df852871a09a6268ced2f"
                      }
                    ],
                    "source": "REFERENCES_TAG",
                    "original_tag": "v3.6.2"
                  },
                  {
                    "cpe": "cpe:2.3:a:b3log:siyuan:*:*:*:*:*:*:*:*",
                    "range": [
                      {
                        "introduced": "3.6.0"
                      },
                      {
                        "fixed": "3.6.2"
                      }
                    ],
                    "source": "CPE_RANGE"
                  }
                ]
              }
            }
          ],
          "versions": [
            "v3.6.1",
            "v3.6.0"
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-34605.json"
          }
        }
      ],
      "modified": "2026-10-28T02:30:23.381561395Z",
      "provider": "osv",
      "references": [
        "https://github.com/siyuan-note/siyuan/releases/tag/v3.6.2",
        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/34xxx/CVE-2026-34605.json",
        "https://github.com/siyuan-note/siyuan/security/advisories/GHSA-73g7-86qr-jrg3",
        "https://nvd.nist.gov/vuln/detail/CVE-2026-34605",
        "https://github.com/siyuan-note/siyuan/issues/17246"
      ],
      "provider_metadata": {
        "cwe_ids": [
          "CWE-79"
        ],
        "cna_assigner": "GitHub_M",
        "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/34xxx/CVE-2026-34605.json"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2026-34605",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 489598,
  "published_at": "2026-03-31T21:50:10.076+00:00"
}