CVE-2026-27589

Description

Caddy is an extensible server platform that uses TLS by default. Prior to version 2.11.1, the local caddy admin API (default listen `127.0.0.1:2019`) exposes a state-changing `POST /load` endpoint that replaces the entire running configuration. When origin enforcement is not enabled (`enforce_origin` not configured), the admin endpoint accepts cross-origin requests (e.g., from attacker-controlled web content in a victim browser) and applies an attacker-supplied JSON config. This can change the admin listener settings and alter HTTP server behavior without user intent. Version 2.11.1 contains a fix for the issue.

References

https://github.com/user-attachments/files/25079820/PR_DESCRIPTION.md

https://github.com/user-attachments/files/25079818/poc.zip

https://github.com/caddyserver/caddy/security/advisories/GHSA-879p-475x-rqh2

https://github.com/caddyserver/caddy/releases/tag/v2.11.1

Details

Source: Mitre, NVD

Risk Information

CVSS v2

CVSS v3

CVSS v4

EPSS