Bugsink: SSRF bypass in `validate_webhook_url`

{
  "id": "ca42bb34bad005b9699d61a7ff29c6b1a64faf1bb6e677b6dbf3eadd6b20d4c1",
  "url": "https://osv.dev/vulnerability/CVE-2026-44502",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "Bugsink: SSRF bypass in `validate_webhook_url`",
    "summary": "Bugsink is a self-hosted error tracking tool. Prior to 2.1.3, Bugsink’s webhook URL validation could be (partially) bypassed because of a mismatch in URL parsing. The original validation logic parsed webhook URLs with Python’s urllib.parse.urlparse, then sent the request with requests.post. For malformed inputs involving backslashes and @, those components can disagree about where the authority ends and which hostname is the real target. A URL may therefore appear to target an allowlisted public hostname during validation, while the HTTP client actually connects to a different host. This vulnerability is fixed in 2.1.3.",
    "evidence": "osv:CVE-2026-44502",
    "products": [],
    "severity": "medium",
    "structured": {
      "id": "CVE-2026-44502",
      "aliases": [
        "CVE-2026-44502",
        "GHSA-fp53-qcf8-2xx2",
        "PYSEC-2026-2405"
      ],
      "metrics": [
        {
          "type": "CVSS_V3",
          "score": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://github.com/bugsink/bugsink",
              "type": "GIT",
              "events": [
                {
                  "introduced": "0"
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                {
                  "fixed": "940d2df635e06803ef658666d734306942db5cc7"
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                "extracted_events": [
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                    "range": [
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                        "introduced": "0"
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                        "fixed": "2.1.3"
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                    "source": "AFFECTED_FIELD",
                    "strategy": "StringRangeExpression"
                  },
                  {
                    "range": [
                      {
                        "fixed": "940d2df635e06803ef658666d734306942db5cc7"
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                    "source": "REFERENCES_COMMIT"
                  },
                  {
                    "range": [
                      {
                        "fixed": "940d2df635e06803ef658666d734306942db5cc7"
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                    ],
                    "source": "REFERENCES_TAG",
                    "original_tag": "2.1.3"
                  },
                  {
                    "range": [
                      {
                        "introduced": "0"
                      },
                      {
                        "fixed": "2.1.3"
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                    "source": "DESCRIPTION"
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          "versions": [
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            "2.1.1",
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            "2.0.14",
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          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-44502.json"
          }
        }
      ],
      "modified": "2026-10-28T02:30:32.995637242Z",
      "provider": "osv",
      "references": [
        "https://github.com/bugsink/bugsink/releases/tag/2.1.3",
        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/44xxx/CVE-2026-44502.json",
        "https://github.com/bugsink/bugsink/security/advisories/GHSA-fp53-qcf8-2xx2",
        "https://nvd.nist.gov/vuln/detail/CVE-2026-44502",
        "https://github.com/bugsink/bugsink/commit/940d2df635e06803ef658666d734306942db5cc7"
      ],
      "provider_metadata": {
        "cwe_ids": [
          "CWE-918"
        ],
        "cna_assigner": "GitHub_M",
        "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/44xxx/CVE-2026-44502.json"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2026-44502",
        "evidence": "/id"
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    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 500012,
  "published_at": "2026-05-26T16:13:32.35+00:00"
}