CVE-2026-27586: fallo de gravedad alta en caddyserver caddy
Caddy's mTLS client authentication silently fails open when CA certificate file is missing or malformed
Publicada el · Actualizada el
Aviso por correo cuando entre en el KEV, tenga PoC pública o suba de nota.
21Vexday Risk Score
Sin señal de explotación. Ningún artefacto público de explotación conocido hasta ahora.
ssvc Trackcvss 8.8epss 0.3%
Caddy is an extensible server platform that uses TLS by default. Prior to version 2.11.1, two swallowed errors in `ClientAuthentication.provision()` cause mTLS client certificate authentication to silently fail open when a CA certificate file is missing, unreadable, or malformed. The server starts without error but accepts any client certificate signed by any system-trusted CA, completely bypassing the intended private CA trust boundary. Any deployment using `trusted_ca_cert_file` or `trusted_ca_certs_pem_files` for mTLS will silently degrade to accepting any system-trusted client certificate if the CA file becomes unavailable. This can happen due to a typo in the path, file rotation, corruption, or permission changes. The server gives no indication that mTLS is misconfigured. Version 2.11.1 fixes the vulnerability.
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N/E:P
Productos afectados
caddyserver · caddyCVEs relacionadas — caddyserver caddy
En el mismo producto, de las más peligrosas a las menos.
CVE-2026-45135HIGHCaddy: Unsafe Unicode Handling in FastCGI splitPos Allows Execution of Non-PHP FilesEPSS 0.7%CVE-2026-52844HIGHCaddy: Windows `file_server` path authorization bypass via encoded backslashEPSS 0.6%CVE-2026-27590HIGHCaddy: Unicode case-folding length expansion causes incorrect split_path index (SCRIPT_NAME/PATH_INFO confusion) in FastCGI transportEPSS 0.6%CVE-2026-55458LOWCaddy: RFC 7230 §6.1 compliance issue / Hop-by-hop headers that leak throughEPSS 0.5%CVE-2026-77281MEDIUMCaddy: rewrite placeholder re-expansionEPSS 0.5%CVE-2026-30852MEDIUMCaddy: vars_regexp double-expands user input, leaking env vars and filesEPSS 0.5%