CVE-2026-27589
Caddy vulnerable to cross-origin config application via local admin API /load (caddy)
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.
INFO
Published Date :
Feb. 24, 2026, 5:29 p.m.
Last Modified :
Feb. 25, 2026, 5:08 p.m.
Remotely Exploit :
Yes !
Source :
[email protected]
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS 3.1 | MEDIUM | [email protected] | ||||
| CVSS 4.0 | MEDIUM | [email protected] |
Solution
- Update Caddy to version 2.11.1 or later.
- Ensure 'enforce_origin' is enabled on the admin API.
- Review and secure admin API access controls.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-27589.
| URL | Resource |
|---|---|
| https://github.com/caddyserver/caddy/releases/tag/v2.11.1 | Release Notes |
| https://github.com/caddyserver/caddy/security/advisories/GHSA-879p-475x-rqh2 | Exploit Mitigation Vendor Advisory |
| https://github.com/user-attachments/files/25079818/poc.zip | Exploit |
| https://github.com/user-attachments/files/25079820/PR_DESCRIPTION.md | Exploit Third Party Advisory |
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-27589 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-27589
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-27589 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-27589 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
Initial Analysis by [email protected]
Feb. 25, 2026
Action Type Old Value New Value Added CVSS V3.1 AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:N Added CPE Configuration OR *cpe:2.3:a:caddyserver:caddy:*:*:*:*:*:*:*:* versions up to (excluding) 2.11.1 Added Reference Type GitHub, Inc.: https://github.com/caddyserver/caddy/releases/tag/v2.11.1 Types: Release Notes Added Reference Type GitHub, Inc.: https://github.com/caddyserver/caddy/security/advisories/GHSA-879p-475x-rqh2 Types: Exploit, Mitigation, Vendor Advisory Added Reference Type GitHub, Inc.: https://github.com/user-attachments/files/25079818/poc.zip Types: Exploit Added Reference Type GitHub, Inc.: https://github.com/user-attachments/files/25079820/PR_DESCRIPTION.md Types: Exploit, Third Party Advisory -
New CVE Received by [email protected]
Feb. 24, 2026
Action Type Old Value New Value Added 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. Added CVSS V4.0 AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N/E:P/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 Added CWE CWE-352 Added Reference https://github.com/caddyserver/caddy/releases/tag/v2.11.1 Added Reference https://github.com/caddyserver/caddy/security/advisories/GHSA-879p-475x-rqh2 Added Reference https://github.com/user-attachments/files/25079818/poc.zip Added Reference https://github.com/user-attachments/files/25079820/PR_DESCRIPTION.md