Caddyserver: >> Caddy Security Vulnerabilities
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. Version 2.11.1 fixes the issue.
CVSS Score
6.9
EPSS Score
0.003
Published
2026-02-24
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 Score
8.8
EPSS Score
0.003
Published
2026-02-24
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 attacker can bypass path-based routing and any access controls attached to that route by changing the casing of the request path. Version 2.11.1 contains a fix for the issue.
CVSS Score
7.7
EPSS Score
0.004
Published
2026-02-24
The caddy-geo-ip (aka GeoIP) middleware through 0.6.0 for Caddy 2, when trust_header X-Forwarded-For is used, allows attackers to spoof their source IP address via an X-Forwarded-For header, which may bypass a protection mechanism (trusted_proxy directive in reverse_proxy or IP address range restrictions).
CVSS Score
6.5
EPSS Score
0.007
Published
2023-12-10
CVE-2023-44487
The HTTP/2 protocol allows a denial of service (server resource consumption) because request cancellation can reset many streams quickly, as exploited in the wild in August through October 2023.
Known exploited
CVSS Score
7.5
EPSS Score
1.0
Published
2023-10-10
Caddy v2.4.6 was discovered to contain an open redirection vulnerability which allows attackers to redirect users to phishing websites via crafted URLs.
CVSS Score
6.1
EPSS Score
0.014
Published
2023-02-06
An out-of-bounds read in the rewrite function at /modules/caddyhttp/rewrite/rewrite.go in Caddy v2.5.1 allows attackers to cause a Denial of Service (DoS) via a crafted URI. Note: This has been disputed as a bug, not a security vulnerability, in the Caddy web server that emerged when an administrator's bad configuration containing a malformed request URI caused the server to return an empty reply instead of a valid HTTP response to the client.
CVSS Score
7.5
EPSS Score
0.01
Published
2022-07-22
Caddy v2.4 was discovered to contain an open redirect vulnerability. A remote unauthenticated attacker may exploit this vulnerability to redirect users to arbitrary web URLs by tricking the victim users to click on crafted links.
CVSS Score
6.1
EPSS Score
0.01
Published
2022-06-02
Caddy before 0.10.13 mishandles TLS client authentication, as demonstrated by an authentication bypass caused by the lack of the StrictHostMatching mode.
CVSS Score
9.8
EPSS Score
0.027
Published
2020-06-15
Caddy through 0.11.0 sends incorrect certificates for certain invalid requests, making it easier for attackers to enumerate hostnames. Specifically, when unable to match a Host header with a vhost in its configuration, it serves the X.509 certificate for a randomly selected vhost in its configuration. Repeated requests (with a nonexistent hostname in the Host header) permit full enumeration of all certificates on the server. This generally permits an attacker to easily and accurately discover the existence of and relationships among hostnames that weren't meant to be public, though this information could likely have been discovered via other methods with additional effort.
CVSS Score
3.7
EPSS Score
0.009
Published
2018-11-10