Vulnerability 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.
CVSS Score
HIGH
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Caddyserver | Caddy | >= 2.7.0, < 2.11.3 |
Related Weaknesses (CWE)
References
- https://github.com/caddyserver/caddy/security/advisories/GHSA-m675-2p33-xv9gExploitVendor Advisory
- https://github.com/caddyserver/caddy/security/advisories/GHSA-m675-2p33-xv9gExploitVendor Advisory
FAQ
What is CVE-2026-45135?
CVE-2026-45135 is a vulnerability with a CVSS score of 8.1 (HIGH). 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/t...
How severe is CVE-2026-45135?
CVE-2026-45135 has been rated HIGH with a CVSS base score of 8.1/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2026-45135?
Check the references section above for vendor advisories and patch information. Affected products include: Caddyserver Caddy.