CVE-2026-27589

Name: CVE-2026-27589
Creator: NVD / NIST
Published: 2026-02-24T17:29:04.317+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

MEDIUMCVSS 6.9/10EPSS 0.17%

Last modified Jun 17, 2026

CVE-2026-27589 is a medium-severity vulnerability rated 6.9/10 on the CVSS scale. 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. EPSS estimates a 0.17% chance of exploitation in the next 30 days.

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.

Metrics

CVSS 3.1

6.5/10

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:N

CVSS 4.0

6.9/10

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/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

EPSS Probability

0.17%

6.2th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-352

Affected Software

Vendor	Product	Versions
Caddyserver	Caddy	< 2.11.1

References

https://github.com/caddyserver/caddy/releases/tag/v2.11.1Release Notes
https://github.com/caddyserver/caddy/security/advisories/GHSA-879p-475x-rqh2Exploit, Mitigation, Vendor Advisory
https://github.com/user-attachments/files/25079818/poc.zipExploit
https://github.com/user-attachments/files/25079820/PR_DESCRIPTION.mdExploit, Third Party Advisory

Timeline

Published: Feb 24, 2026
Last Modified: Jun 17, 2026
Status: Analyzed

Frequently Asked Questions

What is CVE-2026-27589?

How severe is CVE-2026-27589?

CVE-2026-27589 has a CVSS score of 6.9/10 (MEDIUM severity). The EPSS model estimates a 0.17% probability of exploitation in the next 30 days.

How do I fix CVE-2026-27589?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2026-27589?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST