Improper Input Validation Affecting caddy package, versions <2.11.1-r0


Severity

Recommended
0.0
critical
0
10

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Threat Intelligence

EPSS
0.19% (42nd percentile)

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  • Snyk IDSNYK-MINIMOSLATEST-CADDY-15365341
  • published1 Mar 2026
  • disclosed24 Feb 2026

Introduced: 24 Feb 2026

NewCVE-2026-27590  (opens in a new tab)
CWE-20  (opens in a new tab)
CWE-180  (opens in a new tab)

How to fix?

Upgrade Minimos:latest caddy to version 2.11.1-r0 or higher.

NVD Description

Note: Versions mentioned in the description apply only to the upstream caddy package and not the caddy package as distributed by Minimos. See How to fix? for Minimos:latest relevant fixed versions and status.

Caddy is an extensible server platform that uses TLS by default. Prior to version 2.11.1, Caddy's FastCGI path splitting logic computes the split index on a lowercased copy of the request path and then uses that byte index to slice the original path. This is unsafe for Unicode because strings.ToLower() can change UTF-8 byte length for some characters. As a result, Caddy can derive an incorrect SCRIPT_NAME/SCRIPT_FILENAME and PATH_INFO, potentially causing a request that contains .php to execute a different on-disk file than intended (path confusion). In setups where an attacker can control file contents (e.g., upload features), this can lead to unintended PHP execution of non-.php files (potential RCE depending on deployment). Version 2.11.1 fixes the issue.

CVSS Base Scores

version 3.1