{
    "dataType": "CVE_RECORD",
    "dataVersion": "5.2",
    "cveMetadata": {
        "cveId": "CVE-2026-52767",
        "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
        "state": "PUBLISHED",
        "assignerShortName": "GitHub_M",
        "dateReserved": "2026-06-08T17:13:43.064Z",
        "datePublished": "2026-09-04T23:40:39.725Z",
        "dateUpdated": "2026-09-04T23:40:39.725Z"
    },
    "containers": {
        "cna": {
            "title": "YesWiki: Unauthenticated ActivityPub Signature-Verification Bypass via `!openssl_verify(...)` accepting `int(-1)`",
            "problemTypes": [
                {
                    "descriptions": [
                        {
                            "cweId": "CWE-347",
                            "lang": "en",
                            "description": "CWE-347: Improper Verification of Cryptographic Signature",
                            "type": "CWE"
                        }
                    ]
                }
            ],
            "metrics": [
                {
                    "cvssV3_1": {
                        "attackComplexity": "LOW",
                        "attackVector": "NETWORK",
                        "availabilityImpact": "LOW",
                        "baseScore": 8.2,
                        "baseSeverity": "HIGH",
                        "confidentialityImpact": "NONE",
                        "integrityImpact": "HIGH",
                        "privilegesRequired": "NONE",
                        "scope": "UNCHANGED",
                        "userInteraction": "NONE",
                        "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:L",
                        "version": "3.1"
                    }
                }
            ],
            "references": [
                {
                    "name": "https://github.com/YesWiki/yeswiki/security/advisories/GHSA-mv28-wj57-f57g",
                    "tags": [
                        "x_refsource_CONFIRM"
                    ],
                    "url": "https://github.com/YesWiki/yeswiki/security/advisories/GHSA-mv28-wj57-f57g"
                },
                {
                    "name": "https://github.com/YesWiki/yeswiki/commit/d1795e0301e1a1078f17b4b98f56fff70de2029e",
                    "tags": [
                        "x_refsource_MISC"
                    ],
                    "url": "https://github.com/YesWiki/yeswiki/commit/d1795e0301e1a1078f17b4b98f56fff70de2029e"
                },
                {
                    "name": "https://github.com/YesWiki/yeswiki/releases/tag/v4.6.6",
                    "tags": [
                        "x_refsource_MISC"
                    ],
                    "url": "https://github.com/YesWiki/yeswiki/releases/tag/v4.6.6"
                }
            ],
            "affected": [
                {
                    "vendor": "YesWiki",
                    "product": "yeswiki",
                    "versions": [
                        {
                            "version": ">= 4.6.2, < 4.6.6",
                            "status": "affected"
                        }
                    ]
                }
            ],
            "providerMetadata": {
                "orgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
                "shortName": "GitHub_M",
                "dateUpdated": "2026-09-04T23:40:39.725Z"
            },
            "descriptions": [
                {
                    "lang": "en",
                    "value": "YesWiki is a wiki system written in PHP. From version 4.6.2 to before version 4.6.6, HttpSignatureService::verifySignature() checks the result of PHP's openssl_verify() with a loose boolean negation - if (!openssl_verify(...)) { throw ... }. PHP's openssl_verify has four possible return values: 1, 0, -1, and \"false\". The -1 row is the bypass: PHP's truthiness rules make -1 a truthy value, so !(-1) === false, the throw is skipped, and the controller proceeds to processActivity(). Any condition that makes OpenSSL's EVP_VerifyFinal() return -1 triggers the bypass. The reachable consequence is the controller silently treats a failed verification as success and processes the attacker's payload. This issue has been patched in version 4.6.6."
                }
            ],
            "source": {
                "advisory": "GHSA-mv28-wj57-f57g",
                "discovery": "UNKNOWN"
            }
        }
    }
}