Improper Handling of Case Sensitivity Affecting github.com/caddyserver/caddy/v2/modules/caddyhttp/reverseproxy/fastcgi package, versions >=2.7.0 <2.11.3
Threat Intelligence
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.
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Test your applications- Snyk IDSNYK-GOLANG-GITHUBCOMCADDYSERVERCADDYV2MODULESCADDYHTTPREVERSEPROXYFASTCGI-17706416
- published30 Jun 2026
- disclosed18 May 2026
- creditUnknown
Introduced: 18 May 2026
CVE-2026-45135 (opens in a new tab)How to fix?
Upgrade github.com/caddyserver/caddy/v2/modules/caddyhttp/reverseproxy/fastcgi to version 2.11.3 or higher.
Overview
Affected versions of this package are vulnerable to Improper Handling of Case Sensitivity via the splitPos function. An attacker can execute arbitrary code by uploading a file with a specially crafted Unicode filename and accessing it through a crafted URL, causing the FastCGI handler to treat a non-script file as executable. This is only exploitable if the attacker can place files with arbitrary names on the server that are accessible via FastCGI.