CVE-2026-27588 - Vulnerability Analysis

Overview

Caddy < 2.11.1 contains a host header case sensitivity issue caused by an optimized matching path with large host lists, letting attackers bypass host-based routing and access controls by changing Host header casing.

Severity & Score

Impact

Attackers can bypass host-based routing and access controls, potentially accessing unauthorized resources.

Mitigation

Update to version 2.11.1 or later.

References

• https://github.com/caddyserver/caddy/releases/tag/v2.11.1
• https://github.com/caddyserver/caddy/security/advisories/GHSA-x76f-jf84-rqj8

Social Media Activity(1 post)

TheHackerWire

@thehackerwire

Feb 25, 2026

🔴 CVE-2026-27588 - Critical (9.1) 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 du... 🔗 https://www.thehackerwire.com/vulnerability/CVE-2026-27588/ #CVE #vulnerability #infosec #cybersecurity #security #Tenda #patchstack

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