CVE-2026-52844
Caddy: Windows `file_server` path authorization bypass via encoded backslash
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.
INFO
Published Date :
June 23, 2026, 6:18 p.m.
Last Modified :
Oct. 25, 2026, 11:10 p.m.
Remotely Exploit :
Yes !
Source :
[email protected]
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS | 134c704f-9b21-4f2e-91b3-4a467353bcc0 | |||||
| CVSS 3.1 | HIGH | [email protected] |
Solution
- Update Caddy to 2.11.4 or later.
- Verify path matcher and file server behavior.
- Review access control configurations.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-52844.
| URL | Resource |
|---|---|
| https://github.com/caddyserver/caddy/security/advisories/GHSA-qrp7-cvwr-j2c6 | Third Party Advisory Exploit |
| https://github.com/caddyserver/caddy/security/advisories/GHSA-qrp7-cvwr-j2c6 | Third Party Advisory Exploit |
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-52844 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-52844
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-52844 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-52844 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
CVE Translated by [email protected]
Oct. 25, 2026
Action Type Old Value New Value Added Translation Title: caddy de caddyserver, Description: Caddy es una plataforma de servidor extensible que usa TLS por defecto. Antes de la versión 2.11.4, en Windows, los emparejadores de rutas de Caddy tratan /private\secret.txt como fuera de /private/*, pero file_server luego resuelve la misma ruta de solicitud como private\secret.txt en el disco. Un cliente remoto no autenticado puede eludir las rutas de auth/deny con ámbito de ruta de Caddy que protegen /private/*. Esta vulnerabilidad se corrige en la versión 2.11.4. -
Initial Analysis by [email protected]
Jun. 29, 2026
Action Type Old Value New Value Added CPE Configuration AND OR *cpe:2.3:a:caddyserver:caddy:*:*:*:*:*:*:*:* versions up to (excluding) 2.11.4 OR cpe:2.3:o:microsoft:windows:-:*:*:*:*:*:*:* Added Reference Type GitHub, Inc.: https://github.com/caddyserver/caddy/security/advisories/GHSA-qrp7-cvwr-j2c6 Types: Exploit, Third Party Advisory Added Reference Type CISA-ADP: https://github.com/caddyserver/caddy/security/advisories/GHSA-qrp7-cvwr-j2c6 Types: Exploit, Third Party Advisory -
CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0
Jun. 23, 2026
Action Type Old Value New Value Added Reference https://github.com/caddyserver/caddy/security/advisories/GHSA-qrp7-cvwr-j2c6 Added SSVC {'id': 'CVE-2026-52844', 'role': 'CISA Coordinator', 'options': [{'exploitation': 'poc'}, {'automatable': 'yes'}, {'technicalImpact': 'partial'}], 'version': '2.0.3', 'timestamp': '2026-06-23T20:05:58.401415Z'} -
New CVE Received by [email protected]
Jun. 23, 2026
Action Type Old Value New Value Added Affected [{'vendor': 'caddyserver', 'product': 'caddy', 'versions': [{'status': 'affected', 'version': '< 2.11.4'}]}] Added 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. Added CVSS V3.1 AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N Added CWE CWE-22 Added CWE CWE-284 Added Reference https://github.com/caddyserver/caddy/security/advisories/GHSA-qrp7-cvwr-j2c6