CVE-2026-88044

rclone: RC per-server auth-proxy bypass

rclone is a command-line program to sync files and directories to and from different cloud storage providers. From 1.70.0 until 1.75.1, the serve/start RC interface accepts per-server proxyOpt.AuthProxy settings, and the FTP and S3 constructors in cmd/serve/ftp/ftp.go and cmd/serve/s3/server.go incorrectly check the process-global proxy.Opt.AuthProxy value instead. When the global value is empty, the request-local authentication proxy is ignored: FTP falls back to the fixed filesystem with username anonymous and any password, while S3 with AuthKey serves the fixed RC fs rather than the backend selected by the proxy. The dedicated command-line servers that configure the global option are not affected. This issue is fixed in version 1.75.1.

CVSS 3.1 · 9.1 Critical EPSS < 1% KEV · Not listed

Vendors

Rclone

Products

Rclone

CVE-2026-88045

rclone: S3 multipart declared-length memory exhaustion

rclone is a command-line program to sync files and directories to and from different cloud storage providers. From 1.75.0 until 1.75.1, the serve S3 streamed multipart path in cmd/serve/s3/multipart.go passes attacker-controlled contentLength to multipart.NewRW().Reserve before reading request-body bytes. waitForTurn admits the current part and one oversized part when the buffer is empty despite --multipart-streaming-buffer-limit, and lib/pool allocates 1 MiB pages according to Content-Length or X-Amz-Decoded-Content-Length. A network client can retain or multiply these reservations without sending the declared body, exhausting process or host memory or permanently blocking request handlers. Anonymous S3 deployments require no credentials, while deployments using auth_key require an accepted S3 key. This issue is fixed in version 1.75.1.

CVSS 3.1 · 7.5 High EPSS < 1% KEV · Not listed

Vendors

Rclone

Products

Rclone

CVE-2026-71310

rclone: Unbounded HTTP CONNECT Response Headers Can Exhaust rclone Memory

rclone is a command-line program to sync files and directories to and from different cloud storage providers. Prior to 1.75.0, the shared HTTP CONNECT helper in lib/proxy/http.go parses proxy CONNECT responses with http.ReadResponse over an unrestricted buffered reader, allowing a malicious or compromised configured proxy, or an active on-path actor controlling a plaintext HTTP proxy hop, to send oversized headers that grow memory until the rclone process fails. The affected helper is used by FTP and SFTP proxy connections, and SFTP reaches the parser before SSH server authentication, so target host key validation does not constrain a malicious proxy. This issue is fixed in 1.75.0.

CVSS 3.1 · 5.9 Medium EPSS < 1% KEV · Not listed

Vendors

Rclone

Products

Rclone

CVE-2026-79775

rclone Archive Backend SquashFS Parser Denial of Service

rclone versions >= v1.72.0 and <= v1.74.4 (fixed in v1.75.0) contain multiple denial-of-service vulnerabilities in the archive backend's SquashFS parser, which relies on the github.com/diskfs/go-diskfs dependency. The parser fails to validate attacker-controlled superblock and metadata values before use. An attacker who can place or modify a SquashFS image in storage exposed through an rclone :archive: remote can craft a malicious image that triggers an integer division-by-zero panic (zero block size), an out-of-bounds slice panic (out-of-range inode metadata offset), or a non-progress CPU loop (truncated metadata stream). Variants 1 and 2 terminate the rclone process and, via 'rclone serve sftp', can crash the entire SFTP server; variant 3 causes sustained CPU consumption. Parsing is lazy, so a victim or remote client must address or descend into the malicious archive object to trigger it.

CVSS 4.0 · 7.1 High EPSS < 1% KEV · Not listed

Vendors

Rclone

Products

Rclone

CVE-2026-79782

rclone before 1.74.4 Security Token Disclosure via HTTPS to HTTP Redirect

rclone before 1.74.4 fails to strip the X-Amz-Security-Token header when an S3 redirect changes scheme from HTTPS to HTTP on the same host. Attackers can intercept plaintext HTTP traffic to capture AWS STS session tokens sent in request headers.

CVSS 4.0 · 9.3 Critical EPSS < 1% KEV · Not listed

Vendors

Rclone

Products

Rclone

CVE-2026-79777

rclone before v1.75.0 Information Disclosure via RC API

rclone before v1.75.0 includes full Go stack traces in RC API error responses when panics occur. Attackers can trigger panics to leak internal file paths, module versions, goroutine states, and memory addresses.

CVSS 4.0 · 5.1 Medium EPSS < 1% KEV · Not listed

Vendors

Rclone

Products

Rclone

CVE-2026-79779

rclone before v1.75.0 WebDAV Credential Exposure via HTTPS-to-HTTP Redirect

rclone versions before v1.75.0 fail to reject transport downgrades in redirect handling, allowing Basic authorization and Cookie headers to be replayed over plaintext HTTP after same-host HTTPS-to-HTTP redirects. An on-path attacker observing the plaintext hop can capture and reuse credentials to perform WebDAV operations with the compromised account's permissions.

CVSS 4.0 · 6 Medium EPSS < 1% KEV · Not listed

Vendors

Rclone

Products

Rclone

CVE-2026-79776

rclone before 1.75.0 Authentication Bypass via pprof

rclone before 1.75.0 mounts the pprof debug handler as its own router route, bypassing the fail-closed authentication rule in the main handler. Attackers can access the /debug/pprof/cmdline endpoint unauthenticated to retrieve the full process argv including backend credentials.

CVSS 4.0 · 6.9 Medium EPSS < 1% KEV · Not listed

Vendors

Rclone

Products

Rclone

CVE-2026-79783

rclone before 1.74.4 Privilege Escalation via setuid Metadata

rclone before 1.74.4 fails to mask special permission bits when applying source-supplied mode metadata in the local backend, allowing attackers to set setuid/setgid bits on attacker-controlled files. When copying with metadata preservation from an untrusted remote, attackers can plant a setuid binary that escalates privileges to root if rclone runs as root, or to the service account user otherwise.

CVSS 4.0 · 2 Low EPSS < 1% KEV · Not listed

Vendors

Rclone

Products

Rclone

CVE-2026-79781

rclone serve s3 Path Traversal via dot-dot object keys

rclone serve s3 before 1.74.4 contains a path traversal vulnerability that allows attackers to read and overwrite root-level files by using dot-dot segments in S3 object keys. Attackers can send requests with object keys like ../root-secret.txt to escape the bucket namespace and access files in the serve root directory.

CVSS 4.0 · 6.9 Medium EPSS < 1% KEV · Not listed

Vendors

Rclone

Products

Rclone

CVE-2026-79778

rclone before v1.75.0 Denial of Service via TUS nil-response panic

rclone before v1.75.0 contains a denial of service vulnerability in the WebDAV TUS creation handler that dereferences a nil response before checking for transport errors. A malicious or compromised configured endpoint can reset connections during TUS uploads to trigger a panic that terminates unrecovered goroutines and halts unrelated work in long-lived processes.

CVSS 4.0 · 6 Medium EPSS < 1% KEV · Not listed

Vendors

Rclone

Products

Rclone

CVE-2026-79780

rclone before v1.75.0 Credential Exposure via S3 Redirect

rclone before v1.75.0 fails to sanitize IBM IAM bearer tokens and SSE-C encryption keys during S3 redirect callbacks, allowing credentials to be preserved across scheme or host changes. Attackers observing network traffic from a trusted endpoint can capture reusable IBM IAM tokens on same-host HTTPS-to-HTTP downgrades or SSE-C keys on cross-origin redirects to access protected S3 objects.

CVSS 4.0 · 6 Medium EPSS < 1% KEV · Not listed

Vendors

Rclone

Products

Rclone

CVE-2026-71311

rclone: FTP Command Arguments Permit CRLF Injection When Custom Encoding Preserves Newlines

rclone is a command-line program to sync files and directories to and from different cloud storage providers. Prior to 1.75.0, a valid but nondefault FTP filename encoding in backend/ftp/ftp.go can restore raw CR/LF immediately before an attacker-controlled path is interpolated into the line-oriented FTP control channel, and github.com/jlaffaye/ftp formats the argument through textproto.Conn.Cmd without rejecting CR or LF, allowing a filename such as victim CRLF DELE other-secret CRLF NOOP to inject an independent authenticated FTP command when the victim copies or syncs to a more-privileged FTP destination. This issue is fixed in 1.75.0.

CVSS 3.1 · 6.4 Medium EPSS < 1% KEV · Not listed

Vendors

Rclone

Products

Rclone

CVE-2026-71313

rclone: Local Encoding Path Traversal

rclone is a command-line program to sync files and directories to and from different cloud storage providers. From v1.51.0 until v1.75.0, the local backend in backend/local/local.go relies on the configurable filename encoder to prevent remote filename data from becoming operating-system path syntax, so a local destination using Slash, None, Raw, or on Windows an encoding that preserves backslash can decode a standard-encoded fullwidth dot-dot component or native backslash form into an actual parent-directory component before filepath.Join resolves it outside the configured local root, allowing an attacker-controlled source object to create or overwrite files outside the selected destination directory as the rclone process. This issue is fixed in v1.75.0.

CVSS 3.1 · 6.9 Medium EPSS < 1% KEV · Not listed

Vendors

Rclone

Products

Rclone

CVE-2026-71309

rclone: Incomplete path validation allows backend root escape in serve restic

rclone is a command-line program to sync files and directories to and from different cloud storage providers. From 1.40.0 until 1.75.0, rclone serve restic does not correctly reject URL paths beginning with ../ in cmd/serve/restic/restic.go WithRemote, which accepts a leading parent path and passes it to GET, HEAD, POST, and DELETE handlers for configured backends including WebDAV, FTP, HTTP, Memory, and SFTP. An attacker who can access the REST endpoint may read, create, overwrite, or delete objects outside the path configured by the operator when the operator publishes a backend subdirectory and the backend credential can access parent or sibling objects. This issue is fixed in 1.75.0.

CVSS 4.0 · 8.6 High EPSS < 1% KEV · Not listed

Vendors

Rclone

Products

Rclone

CVE-2026-59733

rclone `serve restic --private-repos` authorization bypass: `..` in the URL path lets an authenticated user read, overwrite and delete other users' repositories

Rclone is a command-line program to sync files and directories to and from different cloud storage providers. Prior to 1.74.4, rclone serve restic --private-repos enforces authorization using the routed user path segment while building the backend object key from the raw uncleaned URL path, allowing an authenticated user to include .. in a request such as //..//config and read, overwrite, or delete another user's private repository on backends that clean path components. This issue is fixed in version 1.74.4.

CVSS 3.1 · 8.8 High EPSS < 1% KEV · Not listed

Vendors

Rclone

Products

Rclone

CVE-2026-54572

rclone: Unvalidated symlink target in local `--links` — arbitrary file write from an untrusted remote

Rclone is a command-line program to sync files and directories to and from different cloud storage providers. Prior to 1.74.4, with -l/--links, rclone serializes symlinks as .rclonelink text objects and recreates them on a local destination without validating the target, allowing an attacker-controlled remote to plant an escaping symlink and cause a following object write to land outside the destination with attacker-chosen contents. This issue is fixed in version 1.74.4.

CVSS 3.1 · 7.5 High EPSS < 1% KEV · Not listed

Vendors

Rclone

Products

Rclone

CVE-2026-59732

rclone archive extract allows S3 destination prefix escape via crafted archive paths

Rclone is a command-line program to sync files and directories to and from different cloud storage providers. Prior to 1.74.4, rclone archive extract can write extracted files outside the user-selected destination prefix when extracting a crafted archive containing parent path components such as ../, allowing creation or overwrite of sibling objects in the same bucket or path scope. This issue is fixed in version 1.74.4.

CVSS 3.1 · 5 Medium EPSS < 1% KEV · Not listed

Vendors

Rclone

Products

Rclone

CVE-2026-49980

Rclone: Unauthenticated command execution in `rclone rcd --rc-serve` via inline remote instantiation, bypassing CVE-2026-41179 fix

Rclone is a command-line program to sync files and directories to and from different cloud storage providers. From 1.46.0 until 1.74.3, rclone rcd --rc-serve accepts unauthenticated GET and HEAD requests to paths of the form: /[remote:path]/object. The remote value is parsed from the URL and passed to normal backend initialization. Inline remote configuration can set backend options that execute local commands during initialization. As a result, a single unauthenticated GET or HEAD request can execute a command as the rclone process user. This vulnerability is fixed in 1.74.3.

CVSS 3.1 · 9.8 Critical EPSS < 1% KEV · Not listed

Vendors

Rclone

Products

Rclone

CVE-2026-41179

RClone: Unauthenticated operations/fsinfo allows attacker-controlled backend instantiation and local command execution

Rclone is a command-line program to sync files and directories to and from different cloud storage providers. Starting in version 1.48.0 and prior to version 1.73.5, the RC endpoint `operations/fsinfo` is exposed without `AuthRequired: true` and accepts attacker-controlled `fs` input. Because `rc.GetFs(...)` supports inline backend definitions, an unauthenticated attacker can instantiate an attacker-controlled backend on demand. For the WebDAV backend, `bearer_token_command` is executed during backend initialization, making single-request unauthenticated local command execution possible on reachable RC deployments without global HTTP authentication. Version 1.73.5 patches the issue.

CVSS 4.0 · 9.2 Critical EPSS 8.6% KEV · Not listed

Vendors

Rclone

Products

Rclone