Logo
-

Byte Open Security

(ByteOS Network)

Log In

Sign Up

ByteOS

Security
Vulnerability Details
Registries
Custom Views
Weaknesses
Attack Patterns
Filters & Tools
Vulnerability Details :

CVE-2026-27588

Summary
Assigner-GitHub_M
Assigner Org ID-a0819718-46f1-4df5-94e2-005712e83aaa
Published At-24 Feb, 2026 | 16:28
Updated At-24 Feb, 2026 | 16:28
Rejected At-
Credits

Caddy: MatchHost becomes case-sensitive for large host lists (>100), enabling host-based route/auth bypass

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.

Vendors
-
Not available
Products
-
Metrics (CVSS)
VersionBase scoreBase severityVector
Weaknesses
Attack Patterns
Solution/Workaround
References
HyperlinkResource Type
EPSS History
Score
Latest Score
-
N/A
No data available for selected date range
Percentile
Latest Percentile
-
N/A
No data available for selected date range
Stakeholder-Specific Vulnerability Categorization (SSVC)
▼Common Vulnerabilities and Exposures (CVE)
cve.org
Assigner:GitHub_M
Assigner Org ID:a0819718-46f1-4df5-94e2-005712e83aaa
Published At:24 Feb, 2026 | 16:28
Updated At:24 Feb, 2026 | 16:28
Rejected At:
▼CVE Numbering Authority (CNA)
Caddy: MatchHost becomes case-sensitive for large host lists (>100), enabling host-based route/auth bypass

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.

Affected Products
Vendor
caddyserver
Product
caddy
Versions
Affected
  • < 2.11.1
Problem Types
TypeCWE IDDescription
CWECWE-178CWE-178: Improper Handling of Case Sensitivity
Type: CWE
CWE ID: CWE-178
Description: CWE-178: Improper Handling of Case Sensitivity
Metrics
VersionBase scoreBase severityVector
4.07.7HIGH
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
Version: 4.0
Base score: 7.7
Base severity: HIGH
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
Metrics Other Info
Impacts
CAPEC IDDescription
Solutions
Configurations
Workarounds
Exploits
Credits
Timeline
EventDate
Replaced By
Rejected Reason
References
HyperlinkResource
https://github.com/caddyserver/caddy/security/advisories/GHSA-x76f-jf84-rqj8
x_refsource_CONFIRM
https://github.com/caddyserver/caddy/releases/tag/v2.11.1
x_refsource_MISC
Hyperlink: https://github.com/caddyserver/caddy/security/advisories/GHSA-x76f-jf84-rqj8
Resource:
x_refsource_CONFIRM
Hyperlink: https://github.com/caddyserver/caddy/releases/tag/v2.11.1
Resource:
x_refsource_MISC
Information is not available yet
▼National Vulnerability Database (NVD)
nvd.nist.gov
Source:security-advisories@github.com
Published At:24 Feb, 2026 | 17:29
Updated At:24 Feb, 2026 | 21:52

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.

CISA Catalog
Date AddedDue DateVulnerability NameRequired Action
N/A
Date Added: N/A
Due Date: N/A
Vulnerability Name: N/A
Required Action: N/A
Metrics
TypeVersionBase scoreBase severityVector
Secondary4.07.7HIGH
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
Type: Secondary
Version: 4.0
Base score: 7.7
Base severity: HIGH
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
CPE Matches
Weaknesses
CWE IDTypeSource
CWE-178Primarysecurity-advisories@github.com
CWE ID: CWE-178
Type: Primary
Source: security-advisories@github.com
Evaluator Description
Evaluator Impact

Evaluator Solution

Vendor Statements
References
HyperlinkSourceResource
https://github.com/caddyserver/caddy/releases/tag/v2.11.1security-advisories@github.com
N/A
https://github.com/caddyserver/caddy/security/advisories/GHSA-x76f-jf84-rqj8security-advisories@github.com
N/A
Hyperlink: https://github.com/caddyserver/caddy/releases/tag/v2.11.1
Source: security-advisories@github.com
Resource: N/A
Hyperlink: https://github.com/caddyserver/caddy/security/advisories/GHSA-x76f-jf84-rqj8
Source: security-advisories@github.com
Resource: N/A

Change History

0
Information is not available yet

Similar CVEs

1Records found
CVE-2026-27587
Matching Score-10
Assigner-GitHub, Inc.
ShareView Details
Matching Score-10
Assigner-GitHub, Inc.
CVSS Score-7.7||HIGH
EPSS-Not Assigned
Published-24 Feb, 2026 | 16:26
Updated-24 Feb, 2026 | 21:52
Rejected-Not Available
Known To Be Used In Ransomware Campaigns?-Not Available
KEV Added-Not Available
KEV Action Due Date-Not Available
Caddy: MatchPath %xx (escaped-path) branch skips case normalization, enabling path-based route/auth bypass

Caddy is an extensible server platform that uses TLS by default. Prior to version 2.11.1, Caddy's HTTP `path` request matcher is intended to be case-insensitive, but when the match pattern contains percent-escape sequences (`%xx`) it compares against the request's escaped path without lowercasing. An attacker can bypass path-based routing and any access controls attached to that route by changing the casing of the request path. Version 2.11.1 contains a fix for the issue.

Action-Not Available
Vendor-caddyserver
Product-caddy
CWE ID-CWE-178
Improper Handling of Case Sensitivity
Details not found