CVE-2026-52845: Improper Authentication

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-2026-45692: Partial String Comparison

Caddy is an extensible server platform that uses TLS by default. From 2.4.0 until 2.11.3, the authorization layer and the /config traversal layer do not agree on what object the path refers to. In this case, a path authorized for one config object is accepted, but then resolves to a different...

CVE-2026-52844: Improper Limitation of a Pathname to a Restricted Directory

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-2026-45135: Improper Input Validation

Caddy is an extensible server platform that uses TLS by default. From 2.7.0 until 2.11.3, the FastCGI transport's splitPos in modules/caddyhttp/reverseproxy/fastcgi/fastcgi.go misuses golang.org/x/text/search with search.IgnoreCase when the request path contains a non-ASCII byte. Two distinct fla...

CVE-2026-52846: Improper Encoding or Escaping of Output

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...

Improper Encoding or Escaping of Output

Overview Affected versions of this package are vulnerable to Improper Encoding or Escaping of Output via the stripHTML function. An attacker can inject arbitrary HTML or JavaScript by crafting malformed HTML input that bypasses the tag-stripping logic, which may result in execution of client-side...

GHSA-VCC4-2C75-VC9V Caddy: stripHTML template function bypass

Summary 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 content in the output if it is later rendered as HTML. This may allow...

Caddy: stripHTML template function bypass

Summary 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 content in the output if it is later rendered as HTML. This may allow...

GHSA-QRP7-CVWR-J2C6 Caddy: Windows `file_server` path authorization bypass via encoded backslash

Summary 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 request /private%5csecret.txt and bypass Caddy path-scoped auth/deny routes protecting...

Caddy: Windows `file_server` path authorization bypass via encoded backslash

Summary 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 request /private%5csecret.txt and bypass Caddy path-scoped auth/deny routes protecting...

Access Control Bypass

Overview Affected versions of this package are vulnerable to Access Control Bypass via improper handling of encoded backslashes in request paths on Windows systems. An attacker can access sensitive files within protected directories by crafting requests that use encoded backslash characters to...

Access Control Bypass

Overview Affected versions of this package are vulnerable to Access Control Bypass via improper handling of encoded backslashes in request paths on Windows systems. An attacker can access sensitive files within protected directories by crafting requests that use encoded backslash characters to...

PT-2026-50162

Name of the Vulnerable Software and Affected Versions Caddy versions prior to 2.11.4 Description Caddy is an extensible server platform that uses TLS by default. The stripHTML template function, specifically within the funcStripHTML function, cannot reliably remove all HTML tags from input string...

PT-2026-50160

Name of the Vulnerable Software and Affected Versions Caddy versions prior to 2.11.4 Description On Windows, a mismatch exists between how Caddy path matchers and the file server handle request paths. The MatchPath.MatchWithError function compares the r.URL.Path using URL path semantics and does...

FreeBSD : caddy -- multiple vulnerabilities (94f93681-6775-11f1-8044-002590af0794)

The version of FreeBSD installed on the remote host is prior to tested version. It is, therefore, affected by multiple vulnerabilities as referenced in the 94f93681-6775-11f1-8044-002590af0794 advisory. Caddy project reports: Caddy 2.11.4 contains multiple security fixes. GitHub Security Advisory...

Low: Red Hat Security Advisory: Red Hat Hardened Images RPMs bug fix and enhancement update

An update for Red Hat Hardened Images RPMs is now available. This update includes the following RPMs: caddy: caddy-2.11.4-0.1.hum1 aarch64, x8664 caddy-2.11.4-0.1.hum1.src src...

CVE-2026-52844

creationtimestamp| type| source ---|---|--- 2026-06-08 22:24:46+00:00| published-proof-of-concept| https://github.com/caddyserver/caddy/security/advisories/GHSA-qrp7-cvwr-j2c6 2026-06-23 20:05:07+00:00| seen| https://bsky.app/profile/cve.skyfleet.blue/post/3moy756hrqk2r 2026-06-23 23:10:58+00:00|...

CVE-2026-52846

creationtimestamp| type| source ---|---|--- 2026-06-08 22:24:11+00:00| published-proof-of-concept| https://github.com/caddyserver/caddy/security/advisories/GHSA-vcc4-2c75-vc9v 2026-06-23 20:15:32+00:00| seen| https://bsky.app/profile/cve.skyfleet.blue/post/3moy7pw3teh25...

GHSA-3H23-RRPC-3P87 Caddy Defender trusted proxy client IP bypass

Impact Caddy Defender used r.RemoteAddr when evaluating whether a request should be blocked. RemoteAddr is the address of the immediate peer connected to Caddy. In deployments where Caddy is behind a trusted proxy, CDN, or load balancer, the immediate peer is usually the proxy, not the original...

GHSA-GX7W-56W6-G48X Caddy: Remote Admin Authorization Bypass on PKI Endpoints via Prefix-Based Path Matching

AI Disclosure I used an LLM to help review the source code, reason about attack surface, and help draft and refine this report. I manually validated the finding by reproducing it locally, confirming the vulnerable code path, and verifying the HTTP behavior with curl -v. Summary Caddy's remote adm...