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OpenAdvisories
High · 7.5 CVE-2026-52844 EUVD-2026-38557GHSA-qrp7-cvwr-j2c6GO-2026-5595

Caddy: Windows `file_server` path authorization bypass via encoded backslash

Published Jun 23, 2026 · Updated Jun 23, 2026 · Assigned by GitHub_M

Description

Caddy is an extensible server platform that uses TLS by default. Prior to 2.11.4, on Windows, Caddy path matchers treat /private\secret.txt as outside /private/*, but file_server later resolves the same request path as private\secret.txt on disk. An unauthenticated remote client can bypass Caddy path-scoped auth/deny routes protecting /private/*. This vulnerability is fixed in 2.11.4.

Affected products

VendorProductAffectedFixed
caddyserver caddy < 2.11.4 —

Fixed in Linux distributions

Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.

ReleasePackageFixed inAdvisory
Ubuntu 26.10 caddy No fix yet —
Ubuntu 25.10 caddy No fix yet —
Show 2 more (older releases, extended support, other products)
ReleasePackageFixed inAdvisory
Ubuntu Pro 26.04 LTS caddy No fix yet —
Ubuntu Pro 24.04 LTS caddy No fix yet —
ReleasePackageFixed inAdvisory
SLES for SAP 16.0 govulncheck-vulndb 0.0.20260727T201416-160000.1.1 SUSE-SU-2026:23227-1, SUSE-SU-2026:23216-1
SLES 16.0 govulncheck-vulndb 0.0.20260727T201416-160000.1.1 SUSE-SU-2026:23227-1, SUSE-SU-2026:23216-1
ReleasePackageFixed inAdvisory
openSUSE Leap 16.0 govulncheck-vulndb 0.0.20260727T201416-160000.1.1 openSUSE-SU-2026:21551-1

Affected packages

EcosystemPackageAffectedFixedRecord
Go github.com/caddyserver/caddy <= 1.0.5 — GHSA-qrp7-cvwr-j2c6
Go github.com/caddyserver/caddy/v2 < 2.11.4 2.11.4 GHSA-qrp7-cvwr-j2c6

Advisories 3

References