CVE-2026-27587 — Improper Handling of Case Sensitivity in Caddy

CWE-178 — Improper Handling of Case Sensitivity8 documents6 sources
Severity
7.7HIGHNVD
EPSS
0.1%
top 81.36%
CISA KEV
Not in KEV
Exploit
No known exploits
Affected products
2
Caddyserver CaddyGithub.com Caddyserver Caddy V2
Timeline
PublishedFeb 24
Latest updateFeb 26

Description

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.

CVSS 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

Affected Packages3 packages

▶CVEListV5caddyserver/caddy< 2.11.1
▶NVDcaddyserver/caddy2.10.2 — 2.11.1

🔴Vulnerability Details

5
OSV
Caddy MatchPath %xx branch skips case normalization in github.com/caddyserver/caddy/v2↗2026-02-26
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OSV
CVE-2026-27587: Caddy is an extensible server platform that uses TLS by default↗2026-02-24
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GHSA
Caddy: MatchPath %xx (escaped-path) branch skips case normalization, enabling path-based route/auth bypass↗2026-02-24
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OSV
Caddy: MatchPath %xx (escaped-path) branch skips case normalization, enabling path-based route/auth bypass↗2026-02-24
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CVEList
Caddy: MatchPath %xx (escaped-path) branch skips case normalization, enabling path-based route/auth bypass↗2026-02-24
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📋Vendor Advisories

1
Debian
CVE-2026-27587: caddy - Caddy is an extensible server platform that uses TLS by default. Prior to versio...↗2026
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🕵️Threat Intelligence

1
Wiz
CVE-2026-27587 Impact, Exploitability, and Mitigation Steps | Wiz↗
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CVE-2026-27587 — Improper Handling of Case Sensitivity | cvebase