Cloudreve WebDAV (/dav) has Path Traversal / Broken Access Control — scoped DAV credential escapes its configured account root

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS

7.1 · CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:L/A:N

EPSS

• CVE-2026-54563: 0.32% estimated exploitation activity in the next 30 days; percentile 24.52 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.

As published by the source; long descriptions are shortened.

Summary A Cloudreve WebDAV account stores a uri that defines the account's root folder. The WebDAV request handler (stripPrefix in pkg/webdav/webdav.go) trims the /dav prefix from the request path and joins the remainder to that root with fs.URI.JoinRaw, but never checks that the joined URI stays inside the root. Go's net/http decodes %2e%2e to .. and %2f to / in r.URL.Path before the handler sees it, and JoinRaw resolves .. segments through the standard library's url.URL.JoinPath. A request such as GET /dav/%2e%2e/outside.txt against a credential rooted at cloudreve://my/restricted therefore resolves to cloudreve://my/outside.txt. A scoped DAV credential can read and list files outside its configured folder; a writable scoped credential can also create, overwrite, move, and delete them. The escape stays inside the same Cloudreve user's namespace because downstream DBFS owner checks still apply. It does not cross into another user's files or onto the OS filesystem. What it breaks is…

Published by the source

26 Aug 2026, 15:22 UTC

Last modified by the source

27 Aug 2026, 20:15 UTC

Source last checked

26 Oct 2026, 15:28 UTC

1. Revision 3 · amended · 26 Oct 2026

   Amended from ghsa record GHSA-w5fv-7x5q-g8qp

2. Revision 2 · amended · 24 Oct 2026

   Amended from osv record GO-2026-6298

3. Revision 1 · created · 24 Oct 2026

   Published from osv record GHSA-w5fv-7x5q-g8qp

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# Patch Next advisory brief: CVE-2026-54563

Advisory: Cloudreve WebDAV (`/dav`) has Path Traversal / Broken Access Control — scoped DAV credential escapes its configured account root
IDs: CVE-2026-54563, GHSA-w5fv-7x5q-g8qp
Record: https://patchnext.com/advisories/cve-2026-54563 (revision 3, source checked 26 Oct 2026, 15:28 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: High (CVSS 7.1)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Partial vendor fix; fixed versions by package: github.com/cloudreve/Cloudreve/v4 4.0.0-20260606032813-26b6b1044b02. A vendor fix does not mean a deployment is fixed.

## Affected components
- Go github.com/cloudreve/Cloudreve/v3: affected <= 3.0.0-20250225100611-da4e44b77af4
- Go github.com/cloudreve/Cloudreve: affected every version
- Go github.com/cloudreve/Cloudreve/v4: affected < 4.0.0-20260606032813-26b6b1044b02; fixed in 4.0.0-20260606032813-26b6b1044b02

## Suggested inspection (read-only)
- Go github.com/cloudreve/Cloudreve/v3: check the installed version with your package manager.
- Go github.com/cloudreve/Cloudreve: check the installed version with your package manager.
- Go github.com/cloudreve/Cloudreve/v4: check the installed version with your package manager.

## Supported action
No complete vendor fix is recorded. Follow the primary source's mitigation guidance and check this record again before closing anything.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on github.com/cloudreve/Cloudreve/v3, github.com/cloudreve/Cloudreve, github.com/cloudreve/Cloudreve/v4.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://osv.dev/vulnerability/GHSA-w5fv-7x5q-g8qp (OSV record GHSA-w5fv-7x5q-g8qp lists affected ranges: Go github.com/cloudreve/Cloudreve/v4 >=0 =0 <=3.0.0-20250225100611-da4e44b77af4)
- Verified: https://osv.dev/vulnerability/GO-2026-6298 (OSV record GO-2026-6298 lists affected ranges: Go github.com/cloudreve/Cloudreve >=0; Go github.com/cloudreve/Cloudreve/v3 >=0; Go github.com/cloudreve/Cloudreve/v4 >=0 <4.0.0-20260606032813-26b6b1044b02 (fixed))
- Verified: https://github.com/advisories/GHSA-w5fv-7x5q-g8qp (GitHub-reviewed advisory GHSA-w5fv-7x5q-g8qp lists affected ranges: Go github.com/cloudreve/Cloudreve/v4 >=0 =0 <=3.0.0-20250225100611-da4e44b77af4)

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