CVE-2026-87929: fallo crítico en MaxSite CMS
MaxSite CMS through 109.6 Authentication Bypass via Hardcoded Encryption Key
Publicada el · Actualizada el
Aviso por correo cuando entre en el KEV, tenga PoC pública o suba de nota.
48Vexday Risk Score
Sin señal de explotación. Ella tiene prueba de concepto pública.
ssvc Attendcvss 9.3epss 0.5%
MaxSite CMS through 109.6 ships with a hardcoded session encryption key in application/config/config.php that is never changed during installation, allowing unauthenticated attackers to forge administrator session cookies. Attackers can mint a malicious ci_session cookie with administrator privileges by computing an HMAC-SHA1 using the publicly known encryption key, bypassing authentication checks in is_login() and mso_check_allow() functions.
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
Productos afectados
MaxSite · MaxSite CMSPoCs públicas encontradas — 1
cve_referencegithub.com/EviL0rd/maxsite-cve4/blob/main/2026.09.08-maxsite-cms-hardcoded-session-key-auth-bypass.mdno verificado⚠ Recursos públicos, para evaluar la exposición de sistemas que controlas o estás autorizado a probar. Prueba solo con autorización.
CVEs relacionadas — MaxSite CMS
En el mismo producto, de las más peligrosas a las menos.
CVE-2026-70553CRITICALMaxSite CMS Unauthenticated RCE via Install EndpointEPSS 1.3%CVE-2026-70554CRITICALMaxSite CMS Unauthenticated PHP Object Injection via maxsite_comuser CookieEPSS 1.2%CVE-2026-70552CRITICALMaxSite CMS 109.5 Unauthenticated AJAX Dispatcher Bypass via ajax.phpEPSS 0.8%CVE-2026-87930CRITICALMaxSite CMS through 109.6 PHP Object Injection via ci_sessionEPSS 0.6%CVE-2026-87927HIGHMaxSite CMS through 109.6 Local File Inclusion via ajax dispatcherEPSS 0.6%CVE-2026-87928MEDIUMMaxSite CMS 0.94 through 109.6 HTML Upload XSS via admin_pageEPSS 0.3%
Referencias
https://github.com/EviL0rd/maxsite-cve4/blob/main/2026.09.08-maxsite-cms-hardcoded-session-key-auth-bypass.mdhttps://github.com/maxsite/cmshttps://github.com/maxsite/cms/blob/2ca0a0c7d1d71106a25dbb0f2aedaaefbf12802c/application/config/config.php#L230-L254https://github.com/maxsite/cms/blob/2ca0a0c7d1d71106a25dbb0f2aedaaefbf12802c/application/maxsite/common/core/init.php#L70-L96https://www.vulncheck.com/advisories/maxsite-cms-through-109.6-authentication-bypass-via-hardcoded-encryption-key