CVE-2026-27590 is a critical path confusion vulnerability affecting Caddy server versions prior to 2.11.1. The flaw stems from unsafe Unicode handling in Caddy's FastCGI path splitting logic, which can lead to incorrect script execution. With a CVSS score of 9.8 (Critical), this vulnerability allows unauthenticated attackers to achieve remote code execution in specific configurations where file content can be controlled. While there is no known active exploitation or public exploit code (Metasploit, Nuclei, ExploitDB), the vulnerability has garnered some community discussion and media coverage, indicating awareness.
| Vendor | Product | Version(s) | CPE |
|---|---|---|---|
< 2.11.1CPE matchmatch criteria | cpe:2.3:a:caddyserver:caddy:*:*:*:*:*:*:*:* |
CVSS version used by this source: 4.0
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:P/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
The average CVE in this peer group has 0.0 Twitter, 0.1 Reddit, 0.3 Bluesky, 0.3 Mastodon, and 2.4 GitHub mentions.
The average CVE in this peer group has 0.3 InfoSec Media, 0.0 Vendor Blog, and 0.0 Security Researcher mentions.