Nixpkgs security tracker

Untriaged

Permalink CVE-2026-27588

created 1 month, 3 weeks ago Activity log

Created suggestion 1 month, 3 weeks ago

Caddy: MatchHost becomes case-sensitive for large host lists (>100), enabling host-based route/auth bypass

Caddy is an extensible server platform that uses TLS by default. Prior to version 2.11.1, Caddy's HTTP `host` request matcher is documented as case-insensitive, but when configured with a large host list (>100 entries) it becomes case-sensitive due to an optimized matching path. An attacker can bypass host-based routing and any access controls attached to that route by changing the casing of the `Host` header. Version 2.11.1 contains a fix for the issue.

References

https://github.com/caddyserver/caddy/security/advisories/GHSA-x76f-jf84-rqj8 x_refsource_CONFIRM
https://github.com/caddyserver/caddy/releases/tag/v2.11.1 x_refsource_MISC

Affected products

caddy

==< 2.11.1

Matching in nixpkgs

pkgs.caddy

Fast and extensible multi-platform HTTP/1-2-3 web server with automatic HTTPS

nixos-unstable 2.11.1
- nixpkgs-unstable 2.11.1
- nixos-unstable-small 2.11.1
nixos-25.11 2.10.2
- nixos-25.11-small 2.10.2
- nixpkgs-25.11-darwin 2.10.2

pkgs.xcaddy

Build Caddy with plugins

nixos-unstable 0.4.5
- nixpkgs-unstable 0.4.5
- nixos-unstable-small 0.4.5
nixos-25.11 0.4.5
- nixos-25.11-small 0.4.5
- nixpkgs-25.11-darwin 0.4.5

pkgs.caddyfile-language-server

Basic language server for caddyfile

nixos-unstable 0.4.0
- nixpkgs-unstable 0.4.0
- nixos-unstable-small 0.4.0

pkgs.vimPlugins.nvim-treesitter-parsers.caddy

None

nixos-unstable 0.0.0+rev=2686186
- nixpkgs-unstable 0.0.0+rev=2686186
- nixos-unstable-small 0.0.0+rev=2686186
nixos-25.11 -
- nixos-25.11-small
- nixpkgs-25.11-darwin