CVE-2026-52845 Caddy: FastCGI header normalization bypass in `forward_auth copy_headers`

Caddy is an extensible server platform that uses TLS by default. Prior to 2.11.4, forwardauth copyheaders deletes the exact client-supplied identity header before copying the trusted value from the auth gateway. But when the request later goes through phpfastcgi, Caddy normalizes HTTP headers int...

CVE-2026-52845

Summary (CVE-2026-52845): Caddy 2.11.x contains a bypass in forward_auth copy_headers where, prior to 2.11.4, the exact client-supplied header was deleted but HTTP header names are later normalized to CGI variables, allowing an underscore alias to collide with a trusted header in FastCGI backends...

CVE-2026-52845 Caddy: FastCGI header normalization bypass in `forward_auth copy_headers`

Caddy is an extensible server platform that uses TLS by default. Prior to 2.11.4, forwardauth copyheaders deletes the exact client-supplied identity header before copying the trusted value from the auth gateway. But when the request later goes through phpfastcgi, Caddy normalizes HTTP headers int...

CVE-2026-52845

Caddy is an extensible server platform that uses TLS by default. Prior to 2.11.4, forwardauth copyheaders deletes the exact client-supplied identity header before copying the trusted value from the auth gateway. But when the request later goes through phpfastcgi, Caddy normalizes HTTP headers int...

CVE-2026-52845 Caddy: FastCGI header normalization bypass in `forward_auth copy_headers`

Caddy is an extensible server platform that uses TLS by default. Prior to 2.11.4, forwardauth copyheaders deletes the exact client-supplied identity header before copying the trusted value from the auth gateway. But when the request later goes through phpfastcgi, Caddy normalizes HTTP headers int...

EUVD-2026-38558

Caddy is an extensible server platform that uses TLS by default. Prior to 2.11.4, forwardauth copyheaders deletes the exact client-supplied identity header before copying the trusted value from the auth gateway. But when the request later goes through phpfastcgi, Caddy normalizes HTTP headers int...

CVE-2026-52845

Caddy is an extensible server platform that uses TLS by default. Prior to 2.11.4, forwardauth copyheaders deletes the exact client-supplied identity header before copying the trusted value from the auth gateway. But when the request later goes through phpfastcgi, Caddy normalizes HTTP headers int...

CVE-2026-52844

Caddy is an extensible server platform that uses TLS by default. Prior to 2.11.4, on Windows, Caddy path matchers treat /private\secret.txt as outside /private/, but fileserver later resolves the same request path as private\secret.txt on disk. An unauthenticated remote client can bypass Caddy...

CVE-2026-52844

Caddy is an extensible server platform that uses TLS by default. Prior to 2.11.4, on Windows, Caddy path matchers treat /private\secret.txt as outside /private/, but fileserver later resolves the same request path as private\secret.txt on disk. An unauthenticated remote client can bypass Caddy...

CVE-2026-52844 Caddy: Windows `file_server` path authorization bypass via encoded backslash

Caddy is an extensible server platform that uses TLS by default. Prior to 2.11.4, on Windows, Caddy path matchers treat /private\secret.txt as outside /private/, but fileserver later resolves the same request path as private\secret.txt on disk. An unauthenticated remote client can bypass Caddy...

CVE-2026-52844

CVE-2026-52844 describes a Windows-specific path handling bug in Caddy prior to 2.11.4 where path matchers do not normalize backslashes, causing a request like /private%5csecret.txt to bypass path-scoped auth and reach the protected file, e.g., /private/*, through file_server. The issue is exploi...

EUVD-2026-38557

Caddy is an extensible server platform that uses TLS by default. Prior to 2.11.4, on Windows, Caddy path matchers treat /private\secret.txt as outside /private/, but fileserver later resolves the same request path as private\secret.txt on disk. An unauthenticated remote client can bypass Caddy...

CVE-2026-52844 Caddy: Windows `file_server` path authorization bypass via encoded backslash

Caddy is an extensible server platform that uses TLS by default. Prior to 2.11.4, on Windows, Caddy path matchers treat /private\secret.txt as outside /private/, but fileserver later resolves the same request path as private\secret.txt on disk. An unauthenticated remote client can bypass Caddy...

CVE-2026-52846 Caddy: stripHTML template function bypass

Caddy is an extensible server platform that uses TLS by default. Prior to 2.11.4, Caddy’s stripHTML template function cannot reliably remove all HTML tags from input strings. Certain malformed HTML, such as img src=x onerror=alert, can bypass the tag-stripping logic, potentially leaving dangerous...

CVE-2026-52846 Caddy: stripHTML template function bypass

Caddy is an extensible server platform that uses TLS by default. Prior to 2.11.4, Caddy’s stripHTML template function cannot reliably remove all HTML tags from input strings. Certain malformed HTML, such as img src=x onerror=alert, can bypass the tag-stripping logic, potentially leaving dangerous...

EUVD-2026-38556

Caddy is an extensible server platform that uses TLS by default. Prior to 2.11.4, Caddy’s stripHTML template function cannot reliably remove all HTML tags from input strings. Certain malformed HTML, such as img src=x onerror=alert, can bypass the tag-stripping logic, potentially leaving dangerous...

CVE-2026-52846

Summary: CVE-2026-52846 affects Caddy's stripHTML template function, which cannot reliably strip certain malformed HTML (e.g., <img src=x onerror=alert()>). This can bypass tag-stripping and may enable client-side XSS when untrusted strings are rendered as HTML. The issue originates in func...

CVE-2026-52846

Caddy is an extensible server platform that uses TLS by default. Prior to 2.11.4, Caddy’s stripHTML template function cannot reliably remove all HTML tags from input strings. Certain malformed HTML, such as img src=x onerror=alert, can bypass the tag-stripping logic, potentially leaving dangerous...

CVE-2026-52846

Caddy is an extensible server platform that uses TLS by default. Prior to 2.11.4, Caddy’s stripHTML template function cannot reliably remove all HTML tags from input strings. Certain malformed HTML, such as img src=x onerror=alert, can bypass the tag-stripping logic, potentially leaving dangerous...

CVE-2026-52846 Caddy: stripHTML template function bypass

Caddy is an extensible server platform that uses TLS by default. Prior to 2.11.4, Caddy’s stripHTML template function cannot reliably remove all HTML tags from input strings. Certain malformed HTML, such as img src=x onerror=alert, can bypass the tag-stripping logic, potentially leaving dangerous...