CVE-2026-45135
Description
Caddy is an extensible server platform that uses TLS by default. From 2.7.0 until 2.11.3, the FastCGI transport's splitPos() in modules/caddyhttp/reverseproxy/fastcgi/fastcgi.go misuses golang.org/x/text/search with search.IgnoreCase when the request path contains a non-ASCII byte. Two distinct flaws in that fallback let an attacker mislead Caddy's FastCGI splitting into treating a non-.php (or other configured split_path extension) file as a script. In any deployment where the attacker can place content into a file served via FastCGI (uploads, file storage, etc.), this can be escalated to remote code execution by crafting a URL whose path triggers either flaw. This vulnerability is fixed in 2.11.3.
How to fix
- caddyserver caddy2.11.3 or later
- github.com/caddyserver/caddy/v22.11.3 or later
Affected products
| Product | Affected versions | Fixed in |
|---|---|---|
| caddyserver caddy | 2.7.0 ≤ v < 2.11.3 | 2.11.3 |
| github.com/caddyserver/caddy/v2Go | 2.7.0 ≤ v < 2.11.3 | 2.11.3 |
Check your version
Choose the product and enter the version you run to see whether it falls in the affected range.
Attack Surface Management
See the assets tied to your domains, the technologies they run and known vulnerabilities in one list.