Improper input validation in Caddyserver Caddy
CVE-2026-27585
Caddy is an extensible server platform that uses TLS by default. Prior to version 2.11.1, the path sanitization routine in file matcher doesn't sanitize backslashes which can lead to bypassing path related security protections. It affects users with specific Caddy and environment configurations. Version 2.11.1 fixes the issue.
Vulnerability class: Drupalgeddon 2 (CVE-2018-7600)
Published · last modified .
CVSS v3 metric
CVSS v3 base score 6.5 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N.
EPSS exploit prediction
EPSS: 0.004 (34.5th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 34th percentile — 34.5% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.003 · newest: 0.004 · change: +0.001
Affected products
- Caddyserver Caddy — versions < 2.11.1
Weakness classification (CWE)
References
- github.com/caddyserver/caddy/security/advisories/GHSA-4xrr-hq4w-6vf4 (Exploit, Vendor Advisory)
- github.com/caddyserver/caddy/blob/68d50020eef0d4c3398b878f17c8092ca5b58ca0/modu… (Product)
- github.com/caddyserver/caddy/blob/68d50020eef0d4c3398b878f17c8092ca5b58ca0/modu… (Product)
- github.com/caddyserver/caddy/releases/tag/v2.11.1 (Release Notes)
Frequently asked questions
- What is CVE-2026-27585?
- CVE-2026-27585 is a medium-severity vulnerability in Caddyserver Caddy, classified under Improper Input Validation. CVSS score: 6.5/10. Published 2026-02-24.
- How severe is CVE-2026-27585?
- Medium severity. CVSS v3 base score is 6.5 out of 10.