Case Sensitivity Issue in Caddy Server from Caddy
CVE-2026-27587

7.7HIGH

Key Information:

Vendor

Caddyserver

Status
Caddy
Vendor
CVE Published:
24 February 2026

What is CVE-2026-27587?

Caddy Server prior to version 2.11.1 contains a vulnerability in its HTTP path request matcher, which is designed to function as case-insensitive. However, when the match pattern includes percent-escape sequences, the server incorrectly matches the request's escaped path without converting it to lowercase. This flaw allows malicious actors to exploit case variations in request paths, potentially bypassing configured access controls and routing mechanisms intended to restrict access to specific resources.

Affected Version(s)

caddy < 2.11.1

References

https://github.com/caddyserver/caddy/security/advisories/...
x_refsource_CONFIRM
https://github.com/caddyserver/caddy/releases/tag/v2.11.1
x_refsource_MISC

CVSS V4

Score:
7.7
Severity:
HIGH
Confidentiality:
None
Integrity:
High
Availability:
None
Attack Vector:
Network
Attack Complexity:
Low
Attack Required:
None
Privileges Required:
Undefined
User Interaction:
None

Timeline

  • Vulnerability published

  • Vulnerability Reserved

.