YesWiki: Unauthenticated arbitrary page deletion via `{{erasespamedcomments}}` action

{
  "id": "61c3788feb855d572ab765af4b8aea7fffbbd7f92ff77f7caff94d4d0a9e867a",
  "url": "https://osv.dev/vulnerability/CVE-2026-52766",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "YesWiki: Unauthenticated arbitrary page deletion via `{{erasespamedcomments}}` action",
    "summary": "YesWiki is a wiki system written in PHP. Prior to version 4.6.6, the {{erasespamedcomments}} wiki action (actions/EraseSpamedCommentsAction.php) accepts a suppr[] array from POST and deletes every wiki page whose tag appears in that array, with no authorization check anywhere in the action body or in the page-deletion path it invokes. Combined with YesWiki's allow-by-default action ACL model, any user who has page write access, which is the default for everyone (default_write_acl='*') on a fresh install can permanently delete arbitrary wiki pages, including the front page, admin pages, and pages owned by other users. This issue has been patched in version 4.6.6.",
    "evidence": "osv:CVE-2026-52766",
    "products": [],
    "severity": "critical",
    "structured": {
      "id": "CVE-2026-52766",
      "aliases": [
        "CVE-2026-52766",
        "GHSA-6x7x-gcmf-7r8x"
      ],
      "metrics": [
        {
          "type": "CVSS_V3",
          "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:H"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://github.com/yeswiki/yeswiki",
              "type": "GIT",
              "events": [
                {
                  "introduced": "0"
                },
                {
                  "fixed": "fa81922f4103630911cbea98ead3c4b7bc786e19"
                },
                {
                  "fixed": "ed5b548a705c8091ba0282aaaba73ddda976abef"
                }
              ],
              "database_specific": {
                "extracted_events": [
                  {
                    "range": [
                      {
                        "introduced": "0"
                      },
                      {
                        "fixed": "4.6.6"
                      }
                    ],
                    "source": "AFFECTED_FIELD",
                    "strategy": "StringRangeExpression"
                  },
                  {
                    "range": [
                      {
                        "fixed": "ed5b548a705c8091ba0282aaaba73ddda976abef"
                      }
                    ],
                    "source": "REFERENCES_COMMIT"
                  },
                  {
                    "range": [
                      {
                        "fixed": "fa81922f4103630911cbea98ead3c4b7bc786e19"
                      }
                    ],
                    "source": "REFERENCES_TAG",
                    "original_tag": "v4.6.6"
                  }
                ]
              }
            }
          ],
          "versions": [
            "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-2026-52766.json"
          }
        }
      ],
      "modified": "2026-10-28T02:30:49.444375961Z",
      "provider": "osv",
      "references": [
        "https://github.com/YesWiki/yeswiki/releases/tag/v4.6.6",
        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/52xxx/CVE-2026-52766.json",
        "https://github.com/YesWiki/yeswiki/security/advisories/GHSA-6x7x-gcmf-7r8x",
        "https://nvd.nist.gov/vuln/detail/CVE-2026-52766",
        "https://github.com/YesWiki/yeswiki/commit/ed5b548a705c8091ba0282aaaba73ddda976abef"
      ],
      "provider_metadata": {
        "cwe_ids": [
          "CWE-276",
          "CWE-862"
        ],
        "cna_assigner": "GitHub_M",
        "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/52xxx/CVE-2026-52766.json"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2026-52766",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 517973,
  "published_at": "2026-09-04T23:40:12.087+00:00"
}