Vulnerability · CVE-2026-27587
Caddy is an extensible server platform that uses TLS by default.
Published Feb 24, 2026 · catalog updated Jun 17, 2026 · Caddy is an extensible
Check if you run it
No confirmed exploitation is on record for CVE-2026-27587. EPSS is 0.55%. Act only if a listed version of Caddy is an extensible is installed.
Gaps on this record
- The stored product name is a package slug. The name on this page is taken from the title (Caddy is an extensible).
- No version range is stored. A customer cannot check an installed version against this record.
- No vendor fix or required action is stored. Compare the linked advisory before you change production.
- Severity
- High7.7
- Known exploitation
- Not in CISA/VulnCheck KEV
- EPSS
- 0.55%
- Remediation
- Advisory link
- Affected products
- cpe caddyserver/caddy
Caddy is an extensible server platform that uses TLS by default. Prior to version 2.11.1, Caddy's HTTP request matcher is intended to be case-insensitive, but when the match pattern contains percent-escape sequences ( ) 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.
Are you affected?
Enter the version you run. The result uses only the ranges stored on this record.
The check returns affected, not affected, or incomplete. It does not guess a version that is missing from the record.
- cpe caddyserver/caddyversion unspecified
How to fix CVE-2026-27587
Recommended remediation
A patch or advisory reference is linked. Open the original publisher for availability by product version.
Official advisories
What to do
Three questions, each answered from this record only. Confirm the vendor advisory before you patch.
Should you patch?
No confirmed exploitation is on record for CVE-2026-27587. EPSS is 0.55%. Act only if a listed version of Caddy is an extensible is installed.
Which versions are affected?
Affected version ranges are not on this record. Compare the installed version with the linked vendor advisory before you change production.
What should an analyst verify?
CWE-178. EPSS 0.55%. There is no CISA KEV listing. No Exploit-DB or Metasploit reference is linked. Use the source links for the original advisory.
Code
The project this record applies to. Exploit listings stay in References.
Timeline
Detection, updates, and resolution for this record.
Feb 24, 2026 · NIST NVD
Detected
Caddy is an extensible server platform that uses TLS by default. Prior to version 2.11.1, Caddy's HTTP request matcher is intended to be case-insensitive, but when the match pattern contains percent-escape sequences ( ) 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
Jun 17, 2026 · NIST NVD
Updated
Caddy is an extensible server platform that uses TLS by default. Prior to version 2.11.1, Caddy's HTTP request matcher is intended to be case-insensitive, but when the match pattern contains percent-escape sequences ( ) 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
Sources
- CVE.orgVulnerability recordCVE-2026-27587
Official CVE identifier
cve.org - FIRST EPSSExploitation probabilityCVE-2026-27587
30-day exploitation probability 0.6%
first.org - NIST NVDVulnerability recordCVE-2026-27587
Caddy is an extensible server platform that uses TLS by default. Prior to version 2.11.1, Caddy's HTTP request matcher is intended to be case-insensitive, but when the match pattern contains percent-escape sequences ( ) it compares against the request's escaped path wi
nvd.nist.gov
References
Freshness
Last verified in this catalog Oct 18, 2026. Significant claims (KEV, EPSS, CVSS, affected ranges) come from the source rows above — open the original publisher for the authoritative advisory.