CVE-2026-27588
Caddy: MatchHost becomes case-sensitive for large host lists (>100), enabling host-based route/auth bypass
CVSS Score
0.0
EPSS Score
0.0%
EPSS Percentile
0th
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 host-based routing and any access controls attached to that route by changing the casing of the `Host` header. Version 2.11.1 contains a fix for the issue.
| CWE | CWE-178 |
| Vendor | caddyserver |
| Product | caddy |
| Published | Feb 24, 2026 |
| Last Updated | Feb 27, 2026 |
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Affected Versions
caddyserver / caddy
< 2.11.1