CVE-2026-52767
CVE-2026-52767 · YesWiki: Unauthenticated ActivityPub Signature-Verification Bypass via `!openssl_verify(...)` accepting `int(-1)`
Esta página presenta datos de fuentes públicas de vulnerabilidades. Consulta el aviso original antes de actualizar.
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.
CVSS 8.2 · Alta · EPSS 0,4% · Corrección disponible
- Publicación
- Actualización
Pila tecnológica: php
Productos y versiones afectados
yeswiki
- Versiones
- >= 4.6.2, < 4.6.6: Afectada
Sin corrección publicada
yeswiki/yeswiki Packagist
- Versiones
- v4.6.2
- v4.6.3
- v4.6.4
- v4.6.5
- Intervalos de versiones afectados
- ECOSYSTEM: ≥ 4.6.2, < 4.6.6
Actualiza a 4.6.6