Caddy: Windows `file_server` path authorization bypass via encoded backslash
Published Jun 23, 2026
7.5
HIGHCVSS 3.1
EPSS 0.62%
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
-
- Version < 2.11.4StatusaffectedConstraints-
- Version
Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).
| Vendor | Product | Default status | Versions | ||||||
|---|---|---|---|---|---|---|---|---|---|
| Caddyserver | Caddy | n/a |
|
- < 2.11.4
No data.
No Red Hat product state for this CVE.
github.com/caddyserver/caddy/v2
Go
Introduced 0 Fixed 2.11.4github.com/caddyserver/caddy
Go
Introduced 0 Fixed not fixed
| Ecosystem | Package | Introduced | Fixed |
|---|---|---|---|
| Go | github.com/caddyserver/caddy/v2 | 0 | 2.11.4 |
| Go | github.com/caddyserver/caddy | 0 | not fixed |
Remediation
No remediation recorded yet.
Metrics
No CVSS v4.0 score for this CVE.
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
No CVSS v3.0 score for this CVE.
No CVSS v2.0 score for this CVE.
This CVE is not in the KEV list.
CISA SSVC (Vulnrichment)
Stakeholder-Specific Vulnerability Categorization from CISA ADP.
Exploitation
PoCAutomatable
YesTechnical Impact
PartialDecision
n/aAssessed Jun 23, 2026 · SSVC 2.0.3
Estimated probability of exploitation in the wild in the next 30 days (FIRST EPSS). As of Oct 1, 2026.
Score over time
Jun–Oct 2026- EPSS v4
- EPSS v5
Percentile over time
- EPSS v4
- EPSS v5
Table of values (3 key points)
Flat stretches are collapsed; showing up to 120 newest points.
| Date | Score | Percentile | Model |
|---|---|---|---|
| Oct 1, 2026 | 0.62% (0.00619) | 47.75th | v5 (v2026.06.15) |
| Jun 24, 2026 | 0.40% (0.00396) | 31.31th | v5 (v2026.06.15) |
| Jun 12, 2026 | 0.03% (0.00029) | 8.93th | v4 (v2025.03.14) |
References (3)
- https://github.com/advisories/GHSA-qrp7-cvwr-j2c6 Advisory
- https://github.com/caddyserver/caddy/security/advisories/GHSA-qrp7-cvwr-j2c6 exploitx_refsource_CONFIRMThird Party Advisory
- https://nvd.nist.gov/vuln/detail/CVE-2026-52844
| Link | Providers | Tags |
|---|---|---|
| https://github.com/advisories/GHSA-qrp7-cvwr-j2c6 | Advisory | |
| https://github.com/caddyserver/caddy/security/advisories/GHSA-qrp7-cvwr-j2c6 | exploitx_refsource_CONFIRMThird Party Advisory | |
| https://nvd.nist.gov/vuln/detail/CVE-2026-52844 |
Change history (0)
No recorded changes yet.