CVE-2026-45135 - Caddy: Unsafe Unicode Handling in FastCGI splitPos Allows Execution of Non-PHP Files

[Starburst-David]

CVE ID: CVE-2026-45135
Published: June 23, 2026
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.
Severity: 8.1 | HIGH

More Information:
https://cvefeed.io/vuln/detail/CVE-2026-45135