Improper Handling of Case Sensitivity Affecting github.com/caddyserver/caddy/v2/modules/caddyhttp package, versions <2.11.0
Threat Intelligence
Snyk has a proof-of-concept or detailed explanation of how to exploit this vulnerability.
The probability is the direct output of the EPSS model, and conveys an overall sense of the threat of exploitation in the wild. The percentile measures the EPSS probability relative to all known EPSS scores. Note: This data is updated daily, relying on the latest available EPSS model version. Check out the EPSS documentation for more details.
Do your applications use this vulnerable package?
In a few clicks we can analyze your entire application and see what components are vulnerable in your application, and suggest you quick fixes.
Test your applications- Snyk IDSNYK-GOLANG-GITHUBCOMCADDYSERVERCADDYV2MODULESCADDYHTTP-15346651
- published25 Feb 2026
- disclosed24 Feb 2026
- creditAsim Viladi Oglu Manizada
Introduced: 24 Feb 2026
CVE-2026-27588 Â (opens in a new tab)How to fix?
Upgrade github.com/caddyserver/caddy/v2/modules/caddyhttp to version 2.11.0 or higher.
Overview
Affected versions of this package are vulnerable to Improper Handling of Case Sensitivity in the host request matcher when the host list contains more than 100 entries. An attacker can gain unauthorized access to protected routes and sensitive endpoints by altering the case of the Host header in HTTP requests.
Note: This is only exploitable if the host matcher is configured with more than 100 exact hostnames and is used to enforce access controls.