Upstream information

CVE-2026-27588 at MITRE

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.

SUSE information

Overall state of this security issue: Does not affect SUSE products

This issue is currently rated as having critical severity.

CVSS v3 Scores
CVSS detail National Vulnerability Database
Base Score 9.1
Vector CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N
Attack Vector Network
Attack Complexity Low
Privileges Required None
User Interaction None
Scope Unchanged
Confidentiality Impact High
Integrity Impact High
Availability Impact None
CVSSv3 Version 3.1
CVSS v4 Scores
CVSS detail CNA (GitHub)
Base Score 7.7
Vector 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
Attack Requirements None
Privileges Required None
User Interaction None
Vulnerable System Confidentiality Impact None
Vulnerable System Integrity Impact High
Vulnerable System Availability Impact None
Subsequent System Confidentiality Impact None
Subsequent System Integrity Impact None
Subsequent System Availability Impact None
CVSSv4 Version 4.0
SUSE Bugzilla entry: 1258843 [NEW]

No SUSE Security Announcements cross referenced.


SUSE Timeline for this CVE

CVE page created: Tue Feb 24 20:04:14 2026
CVE page last modified: Thu Feb 26 13:03:48 2026