Goal Reached Thanks to every supporter — we hit 100%!

Goal: 1000 CNY · Raised: 1000 CNY

100.0%
Buy Us a Coffee

CVE-2026-27588— Caddy: MatchHost becomes case-sensitive for large host lists (>100), enabling host-based route/auth bypass

EPSS 0.06% · P19
Get alerts for future matching vulnerabilitiesLog in to subscribe

I. Basic Information for CVE-2026-27588

Vulnerability Information
Have questions about the vulnerability? See if Shenlong's analysis helps!
View Shenlong Deep Dive ↗

Although we use advanced large model technology, its output may still contain inaccurate or outdated information.Shenlong tries to ensure data accuracy, but please verify and judge based on the actual situation.

Vulnerability Title
Caddy: MatchHost becomes case-sensitive for large host lists (>100), enabling host-based route/auth bypass
Source: NVD (National Vulnerability Database)
Vulnerability Description
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.
Source: NVD (National Vulnerability Database)
CVSS Information
N/A
Source: NVD (National Vulnerability Database)
Vulnerability Type
大小写敏感处理不恰当
Source: NVD (National Vulnerability Database)
Vulnerability Title
Caddy 安全漏洞
Source: CNNVD (China National Vulnerability Database)
Vulnerability Description
Caddy是Caddy公司的一款开源、跨平台的HTTP/Web服务器。 Caddy 2.11.1之前版本存在安全漏洞，该漏洞源于HTTP主机请求匹配器在配置大型主机列表时变为大小写敏感，可能导致攻击者绕过基于主机的路由和访问控制。
Source: CNNVD (China National Vulnerability Database)
CVSS Information
N/A
Source: CNNVD (China National Vulnerability Database)
Vulnerability Type
N/A
Source: CNNVD (China National Vulnerability Database)

Affected Products

VendorProductAffected VersionsCPESubscribe
caddyservercaddy < 2.11.1 -

II. Public POCs for CVE-2026-27588

#POC DescriptionSource LinkShenlong Link
AI-Generated POCPremium

No public POC found.

Login to generate AI POC

III. Intelligence Information for CVE-2026-27588

请登录查看更多情报信息。

Same Patch Batch · caddyserver · 2026-02-24 · 6 CVEs total

CVE-2026-27585Caddy's improper sanitization of glob characters in file matcher may lead to bypassing sec
CVE-2026-27586Caddy's mTLS client authentication silently fails open when CA certificate file is missing
CVE-2026-27587Caddy: MatchPath %xx (escaped-path) branch skips case normalization, enabling path-based r
CVE-2026-27590Caddy: Unicode case-folding length expansion causes incorrect split_path index (SCRIPT_NAM
CVE-2026-27589Caddy vulnerable to cross-origin config application via local admin API /load (caddy)

IV. Related Vulnerabilities

Same product: caddy
Same vendor: caddyserver
Same weakness: CWE-178

V. Comments for CVE-2026-27588

No comments yet

Leave a comment