YesWiki before 4.6.7 Authentication Bypass via ActivityPub Inbox Actor Spoofing

{
  "id": "d1dec2782b737d32cc38d92c209cb90c427803a803eb4d3bdc129af9296b1638",
  "url": "https://osv.dev/vulnerability/CVE-2026-104445",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "YesWiki before 4.6.7 Authentication Bypass via ActivityPub Inbox Actor Spoofing",
    "summary": "YesWiki before 4.6.7 contains an authentication bypass vulnerability in the ActivityPub inbox that fails to bind the verified HTTP signature signer to the activity actor. Unauthenticated attackers with any ActivityPub keypair can send signed Delete or Update activities referencing a mirrored entry's sourceUrl to delete or overwrite other actors' federated entries.",
    "evidence": "osv:CVE-2026-104445",
    "products": [],
    "severity": "high",
    "structured": {
      "id": "CVE-2026-104445",
      "aliases": [
        "CVE-2026-104445",
        "GHSA-rm6r-grfg-4v78"
      ],
      "metrics": [
        {
          "type": "CVSS_V4",
          "score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:H/VA:L/SC:N/SI:N/SA:N"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://github.com/yeswiki/yeswiki",
              "type": "GIT",
              "events": [
                {
                  "introduced": "0"
                },
                {
                  "fixed": "07120ed8971047f504f7ec78060828f1895f475f"
                }
              ],
              "database_specific": {
                "extracted_events": [
                  {
                    "range": [
                      {
                        "introduced": "0"
                      },
                      {
                        "fixed": "4.6.7"
                      }
                    ],
                    "source": "AFFECTED_FIELD",
                    "strategy": "StandardRange"
                  },
                  {
                    "range": [
                      {
                        "introduced": "0"
                      },
                      {
                        "fixed": "4.6.7"
                      }
                    ],
                    "source": "DESCRIPTION"
                  }
                ]
              }
            }
          ],
          "versions": [
            "v4.6.6",
            "v4.6.5",
            "v4.6.4",
            "v4.6.3",
            "v4.6.2",
            "v4.6.0",
            "v4.5.5",
            "v4.5.4",
            "v4.5.3",
            "v4.5.2",
            "v4.5.1",
            "v4.4.3",
            "v4.4.2",
            "v4.4.1",
            "v4.4.0",
            "v4.3.1",
            "v4.3.0",
            "v4.2.2",
            "v4.2.1",
            "v4.2.0",
            "v4.1.5",
            "v4.1.0"
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-104445.json"
          }
        }
      ],
      "modified": "2026-10-28T02:30:46.333100469Z",
      "provider": "osv",
      "references": [
        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/104xxx/CVE-2026-104445.json",
        "https://github.com/YesWiki/yeswiki/security/advisories/GHSA-rm6r-grfg-4v78",
        "https://nvd.nist.gov/vuln/detail/CVE-2026-104445",
        "https://www.vulncheck.com/advisories/yeswiki-before-4.6.7-authentication-bypass-via-activitypub-inbox-actor-spoofing"
      ],
      "provider_metadata": {
        "cwe_ids": [
          "CWE-290"
        ],
        "cna_assigner": "VulnCheck",
        "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/104xxx/CVE-2026-104445.json"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2026-104445",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 514182,
  "published_at": "2026-10-02T11:38:19.058+00:00"
}