CVE-2026-27587
CRITICALCaddy < 2.11.1 - Path-Based Routing Bypass via Case Sensitivity Mismatch
Title source: llmDescription
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.
References (2)
Core 2
Core References
Vendor Advisory x_refsource_confirm
https://github.com/caddyserver/caddy/security/advisories/GHSA-g7pc-pc7g-h8jh
Release Notes x_refsource_misc
https://github.com/caddyserver/caddy/releases/tag/v2.11.1
Scores
CVSS v3
9.1
EPSS
0.0037
EPSS Percentile
28.6%
Attack Vector
NETWORK
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N
CISA SSVC
Vulnrichment
Exploitation
poc
Automatable
yes
Technical Impact
partial
Details
CWE
CWE-178
Status
published
Products (2)
caddyserver/caddy
0 - 2.11.1Go
caddyserver/caddy
2.10.2 - 2.11.1
Published
Feb 24, 2026
Tracked Since
Feb 25, 2026