CVE-2026-27589
MEDIUM6.5EPSS 0.03%Caddy is vulnerable to cross-origin config application via local admin API /load in github.com/caddyserver/caddy/v2
Published: 2/24/2026Modified: 4/30/2026
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.
Affected packages (3)
- Debian/caddyfrom 0
- Go/github.com/caddyserver/caddy/v2from 0, < 2.11.1
- Go/github.com/caddyserver/caddy/v2from 0, < 2.11.1
CVSS scores
| Source | Version | Severity | Vector |
|---|---|---|---|
| osv | CVSS 4.0 | — | CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N/E:P |
| osv | CVSS 3.1 | MEDIUM6.5 | CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:N |
References (9)
- ADVISORYhttps://nvd.nist.gov/vuln/detail/CVE-2026-27589
- ADVISORYhttps://security-tracker.debian.org/tracker/CVE-2026-27589
- PATCHhttps://github.com/caddyserver/caddy
- WEBhttps://github.com/caddyserver/caddy/commit/65e0ddc22137bbbaa68c842ae0b98d0548504545
- WEBhttps://github.com/caddyserver/caddy/releases/tag/v2.11.1
- WEBhttps://github.com/caddyserver/caddy/security/advisories/GHSA-879p-475x-rqh2
- WEBhttps://github.com/user-attachments/files/25079818/poc.zip
- WEBhttps://github.com/user-attachments/files/25079820/PR_DESCRIPTION.md
- WEBhttps://pkg.go.dev/vuln/GO-2026-4537