rclone: WebDAV Credentials Survive a Same-Host HTTPS-to-HTTP Redirect
## 1. Summary WebDAV's default redirect handling can replay Basic authorization and configured Cookie headers over plaintext HTTP after a same-host HTTPS-to-HTTP redirect. This was reproduced through the real backend. Unlike the low-impact STS token in rclone's published S3 redirect advisory, Basic passwords and session cookies are complete reusable credentials, supporting a High rating when they grant normal WebDAV read/write access. The credible threat requires a legitimate endpoint, gateway, or accelerator to emit an unsafe redirect and an adjacent/on-path actor to observe the plaintext hop. A report should not rely on a malicious original WebDAV endpoint because that endpoint already receives the credentials. ## 2. Affected Assets & Attack Surface - Backend configuration/authentication: `backend/webdav/webdav.go:127-139`, `170-206`, `440-530` - Shared redirect callback: `lib/rest/rest.go:218-231` - HTTP client: `fs/fshttp/http.go:311-329` - Credentials: Basic passwords, bearer authorization, SharePoint/session cookies, and configured secret headers - Confirmed affected version: `<= v1.74.0-240` ## 3. Technical Root Cause Analysis `PreserveMethodRedirectFn` limits redirect count and restores the original method, but it does not reject a transport downgrade or compare the full origin tuple. The client therefore relies on Go's hostname-oriented sensitive-header forwarding rules. Those rules can preserve `Authorization` and Cookie on a same-host redirect even when the new sch
GO-2026-6197
Revision 1
WebDAV credential leakage on HTTPS to HTTP redirect in github.com/rclone/rclone
WebDAV credential leakage on HTTPS to HTTP redirect in github.com/rclone/rclone
Imported from structured advisory data. Source references identify upstream records or fields; verify affected versions and your deployed configuration.
Security context
Source reference: osv:GO-2026-6197
github.com/rclone/rclone
Source reference: /affected/0/package/name
- Affected versions
- Not stated in this record
- Fixed versions
- 1.75.0
Source reference:
/affected/0/ranges - Prerequisites
- Not stated in this record
Structured affected-version data
Original package identities and version rules from this source.
[
{
"ranges": [
{
"type": "SEMVER",
"events": [
{
"introduced": "0"
},
{
"fixed": "1.75.0"
}
]
}
],
"package": {
"name": "github.com/rclone/rclone",
"purl": "pkg:golang/github.com/rclone/rclone",
"ecosystem": "Go"
},
"database_specific": {
"source": "https://vuln.go.dev/ID/GO-2026-6197.json"
},
"ecosystem_specific": {
"imports": [
{
"path": "github.com/rclone/rclone/backend/webdav",
"symbols": [
"Fs.About",
"Fs.Copy",
"Fs.DirMove",
"Fs.List",
"Fs.ListP",
"Fs.Mkdir",
"Fs.Move",
"Fs.NewObject",
"Fs.Purge",
"Fs.Put",
"Fs.PutStream",
"Fs.Rmdir",
"NewFs",
"Object.CreateUploader",
"Object.ModTime",
"Object.Open",
"Object.Remove",
"Object.SetModTime",
"Object.Size",
"Object.Update",
"Uploader.Upload",
"Uploader.UploadChunk"
]
},
{
"path": "github.com/rclone/rclone/lib/rest",
"symbols": [
"PreserveMethodRedirectFn"
]
}
]
}
}
]- Related CVEs
- CVE-2026-79779
Source reference:
/aliases
Publisher severity
No explicit severity was provided.
- Event
- #15295 · Revision 1
- Added to Heist Feed
- Publisher date
GHSA-h4mf-4v27-hggj
Primary source · Revision 1
Imported from structured advisory data. Source references identify upstream records or fields; verify affected versions and your deployed configuration.
Security context
Source reference: osv:GHSA-h4mf-4v27-hggj
github.com/rclone/rclone
Source reference: /affected/0/package/name
- Affected versions
- Not stated in this record
- Fixed versions
- 1.75.0
Source reference:
/affected/0/ranges - Prerequisites
- Not stated in this record
Structured affected-version data
Original package identities and version rules from this source.
[
{
"ranges": [
{
"type": "SEMVER",
"events": [
{
"introduced": "0"
},
{
"fixed": "1.75.0"
}
]
}
],
"package": {
"name": "github.com/rclone/rclone",
"purl": "pkg:golang/github.com/rclone/rclone",
"ecosystem": "Go"
},
"database_specific": {
"source": "https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/08/GHSA-h4mf-4v27-hggj/GHSA-h4mf-4v27-hggj.json",
"last_known_affected_version_range": "<= 1.74.0"
}
}
]- Related CVEs
- CVE-2026-79779
Source reference:
/aliases
Publisher severity
No explicit severity was provided.
- Event
- #15296 · Revision 1
- Added to Heist Feed
- Publisher date