CVE-2026-27588
Fixed in a distro release EPSS <1%CVSS 7.7
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.
Products: caddyserver caddy
Fixed upstream
| Ecosystem | Package | Fixed in |
|---|---|---|
| Go | github.com/caddyserver/caddy/v2 | 2.11.1 |
Distro releases
| Release | Package | Fixed in |
|---|---|---|
| Debian 12 | caddy | 2.6.2-5+deb12u1 |
| Debian 13 | caddy | 2.6.2-12+deb13u1 |
| Debian 14 | caddy | 2.11.2-1 |
| Ubuntu 25.10 | caddy | no fix |
| Ubuntu 26.10 | caddy | no fix |
| Ubuntu Pro 24.04 LTS | caddy | no fix |
| Ubuntu Pro 26.04 LTS | caddy | no fix |
| openSUSE Leap 15.6 | govulncheck-vulndb | 0.0.20260226T182644-150000.1.149.1 |
| openSUSE Leap 16.0 | govulncheck-vulndb | 0.0.20260723T184607-160000.1.1 |