CVE-2026-27588

HIGH EPSS 28.9%
Published Feb 24, 20264mo ago · Modified Feb 25, 20264mo ago
7.7 CVSS 4.0
High
Find Similar
Published Feb 24, 2026 4mo ago
Last Modified Feb 25, 2026 4mo ago

Description

Caddy is an extensible server platform that uses TLS by default. Prior to version 2.11.1, Caddy's HTTP `host` request matcher is documented as case-insensitive, but when configured with a large host list (>100 entries) it becomes case-sensitive due to an optimized matching path. An attacker can bypass host-based routing and any access controls attached to that route by changing the casing of the `Host` header. Version 2.11.1 contains a fix for the issue.

CVSS Details

Base Score
7.7
Exploitability
—
Impact
—
Vector string
CVSS:4.0/AV:N/AC:L/AT:N/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
Attack Vector Network
Attack Complexity Low
Privileges Required None
User Interaction None
Scope X

Threat Intelligence

EPSS Exploit Probability
28.9% percentile
Exploit & Patch Status
Public Exploit Known
No Patch Available

Weaknesses 1

CWE-178

Affected Products 1

VendorProductVersionRange
caddyservercaddy*≥2.10.2  –  <2.11.1

References 2

  • github.com https://github.com/caddyserver/caddy/releases/tag/v2.11.1
    Release Notes
  • github.com https://github.com/caddyserver/caddy/security/advisories/GHSA-x76f-jf84-rqj8
    ExploitVendor Advisory

Remediation

No remediation data recorded yet

Check vendor advisories and the NVD entry for patch availability.