CVE-2026-45135

Name	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.
Source	CVE (at NVD; CERT, ENISA, LWN, oss-sec, fulldisc, Debian ELTS, Red Hat, Ubuntu, Gentoo, SUSE bugzilla/CVE, GitHub advisories/code/issues, web search, more)
Debian Bugs	1140773

Vulnerable and fixed packages

The table below lists information on source packages.

Source Package	Release	Version	Status
caddy (PTS)	bookworm	2.6.2-5	fixed
	trixie	2.6.2-12	fixed
	trixie (security)	2.6.2-12+deb13u1	fixed
	forky, sid	2.11.4-1	fixed

The information below is based on the following data on fixed versions.

Package	Type	Release	Fixed Version	Debian Bugs
caddy	source	bookworm	(not affected)
caddy	source	trixie	(not affected)
caddy	source	(unstable)	2.11.4-1	1140773

Notes

[trixie] - caddy <not-affected> (Vulnerable code introduced later)
[bookworm] - caddy <not-affected> (Vulnerable code introduced later)
https://github.com/caddyserver/caddy/security/advisories/GHSA-m675-2p33-xv9g
Fixed by: https://github.com/caddyserver/caddy/commit/fb324331f40782ac7a48d83f591c2bb7615d7eed (v2.11.3)
Introduced with: https://github.com/caddyserver/caddy/commit/7c28c0c07ac70a8960a166c7126150a408ba7464 (v2.11.0)
the vulnerable window is 2.11.0 to 2.11.2. 2.6.2's splitPos() is a plain
strings.Index() over a lower-cased copy; that separate flaw is CVE-2026-27590.