Cross-site Request Forgery (CSRF)

Overview Affected versions of this package are vulnerable to Cross-site Request Forgery CSRF through the adminLoad.handleLoad process. An attacker can modify the running configuration and alter server behavior by sending cross-origin requests to the local admin API when origin enforcement is not...

Caddy is vulnerable to cross-origin config application via local admin API /load

commit: e0f8d9b2047af417d8faf354b675941f3dac9891 as-of 2026-02-04 channel: GitHub security advisory per SECURITY.md summary The local caddy admin API default listen 127.0.0.1:2019 exposes a state-changing POST /load endpoint that replaces the entire running configuration. When origin enforcement ...

Improper Handling of Case Sensitivity

Overview Affected versions of this package are vulnerable to Improper Handling of Case Sensitivity in the host request matcher when the host list contains more than 100 entries. An attacker can gain unauthorized access to protected routes and sensitive endpoints by altering the case of the Host...

Caddy: MatchHost becomes case-sensitive for large host lists (>100), enabling host-based route/auth bypass

Summary Caddy's HTTP host request matcher is documented as case-insensitive, but when configured with a large host list 100 entries it becomes case-sensitive due to an optimized matching path. An attacker can bypass host-based routing and any access controls attached to that route by changing the...

GHSA-X76F-JF84-RQJ8 Caddy: MatchHost becomes case-sensitive for large host lists (>100), enabling host-based route/auth bypass

Summary Caddy's HTTP host request matcher is documented as case-insensitive, but when configured with a large host list 100 entries it becomes case-sensitive due to an optimized matching path. An attacker can bypass host-based routing and any access controls attached to that route by changing the...

GHSA-G7PC-PC7G-H8JH Caddy: MatchPath %xx (escaped-path) branch skips case normalization, enabling path-based route/auth bypass

Summary Caddy's HTTP path request matcher is intended to be case-insensitive, but when the match pattern contains percent-escape sequences %xx it compares against the request's escaped path without lowercasing. An attacker can bypass path-based routing and any access controls attached to that rou...

Caddy: MatchPath %xx (escaped-path) branch skips case normalization, enabling path-based route/auth bypass

Summary Caddy's HTTP path request matcher is intended to be case-insensitive, but when the match pattern contains percent-escape sequences %xx it compares against the request's escaped path without lowercasing. An attacker can bypass path-based routing and any access controls attached to that rou...

GHSA-HFFM-G8V7-WRV7 Caddy: mTLS client authentication silently fails open when CA certificate file is missing or malformed

Summary 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,...

Caddy: mTLS client authentication silently fails open when CA certificate file is missing or malformed

Summary 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,...

Unchecked Return Value

Overview Affected versions of this package are vulnerable to Unchecked Return Value due to improper error handling in the provision function. An attacker can gain unauthorized access by presenting a client certificate signed by any system-trusted certificate authority, bypassing the intended...

Improper Neutralization of Equivalent Special Elements

Overview github.com/caddyserver/caddy/v2/modules/caddyhttp/fileserver is a fast and extensible multi-platform HTTP/1-2-3 web server with automatic HTTPS Affected versions of this package are vulnerable to Improper Neutralization of Equivalent Special Elements in matcher.go‎, when matching filenam...

Improper Neutralization of Equivalent Special Elements

Overview Affected versions of this package are vulnerable to Improper Neutralization of Equivalent Special Elements in matcher.go‎, when matching filenames using the tryfiles directive, which does not properly handle backslashes. An attacker can bypass security protections by exploiting glob...

Caddy: Improper sanitization of glob characters in file matcher may lead to bypassing security protections

Summary The path sanitization in file matcher doesn't sanitize backslashes which can lead to bypassing path related security protections. Details The tryfiles directive is used to rewrite the request uri. It accepts a list of patterns and checks if any files exist in the root that match the...

CVE-2026-27588

Caddy is an extensible server platform that uses TLS by default. Prior to version 2.11.1, Caddy's HTTP host request matcher is documented as case-insensitive, but when configured with a large host list 100 entries it becomes case-sensitive due to an optimized matching path. An attacker can bypass...

CVE-2026-27589

Caddy is an extensible server platform that uses TLS by default. Prior to version 2.11.1, the local caddy admin API default listen 127.0.0.1:2019 exposes a state-changing POST /load endpoint that replaces the entire running configuration. When origin enforcement is not enabled enforceorigin not...

CVE-2026-27590

Caddy is an extensible server platform that uses TLS by default. Prior to version 2.11.1, Caddy's FastCGI path splitting logic computes the split index on a lowercased copy of the request path and then uses that byte index to slice the original path. This is unsafe for Unicode because...

CVE-2026-27585

Caddy is an extensible server platform that uses TLS by default. Prior to version 2.11.1, the path sanitization routine in file matcher doesn't sanitize backslashes which can lead to bypassing path related security protections. It affects users with specific Caddy and environment configurations...

CVE-2026-27587

Caddy is an extensible server platform that uses TLS by default. Prior to version 2.11.1, Caddy's HTTP path request matcher is intended to be case-insensitive, but when the match pattern contains percent-escape sequences %xx it compares against the request's escaped path without lowercasing. An...

CVE-2026-27586

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...

CVE-2026-27587

Caddy is an extensible server platform that uses TLS by default. Prior to version 2.11.1, Caddy's HTTP path request matcher is intended to be case-insensitive, but when the match pattern contains percent-escape sequences %xx it compares against the request's escaped path without lowercasing. An...