CVE-2026-41176

Summary

The RC endpoint options/set is exposed without AuthRequired: true, but it can mutate global runtime configuration, including the RC option block itself. An unauthenticated attacker can set rc.NoAuth=true, which disables the authorization gate for many RC methods registered with AuthRequired: true on reachable RC servers that are started without global HTTP authentication. This can lead to unauthorized access to sensitive administrative functionality, including configuration and operational RC methods.

Preconditions

Preconditions for this vulnerability are:

• The rclone remote control API must be enabled, either by the --rc flag or by running the rclone rcd server
• The remote control API must be reachable by the attacker - by default rclone only serves the rc to localhost unless the --rc-addr flag is in use
• The rc must have been deployed without global RC HTTP authentication - so not using --rc-user/--rc-pass/--rc-htpasswd/etc

Details

The root cause is present from v1.45 onward. Some higher-impact exploitation paths became available in later releases as additional RC functionality was introduced.

The issue is caused by two properties of the RC implementation:

1. options/set is exposed without AuthRequired: true
2. the RC server enforces authorization for AuthRequired calls using the mutable runtime value s.opt.NoAuth

Relevant code paths:

• fs/rc/config.go

  • registers options/set without AuthRequired: true
  • rcOptionsSet reshapes attacker-controlled input into global option blocks

• fs/rc/rcserver/rcserver.go

  • request handling checks:
    • if !s.opt.NoAuth && call.AuthRequired && !s.server.UsingAuth()
  • once rc.NoAuth is changed to true, later AuthRequired methods become callable without credentials

This creates a runtime auth-bypass primitive on the RC interface.

After setting rc.NoAuth=true, previously protected administrative methods become callable, including configuration and operational endpoints such as:

• config/listremotes
• config/dump
• config/get
• operations/list
• operations/copyfile
• core/command

Relevant code for the second-stage command execution path:

• fs/metadata.go

  • metadataMapper() uses exec.Command(...)

• fs/operations/rc.go

  • operations/copyfile is normally AuthRequired: true
  • once rc.NoAuth=true, it becomes reachable without credentials

This was validating using the following:

• current master as of 2026-04-14: bf55d5e6d37fd86164a87782191f9e1ffcaafa82
• latest public release tested locally: v1.73.4

The issue was also verified on a public amd64 Ubuntu host controlled by the tester, using direct host execution (not containerized PoC execution).

PoC

Minimal reproduction

Start a vulnerable server:

rclone rcd --rc-addr 127.0.0.1:5572

No --rc-user, no --rc-pass, no --rc-htpasswd.

First confirm that a protected RC method is initially blocked:

curl -sS -X POST http://127.0.0.1:5572/config/listremotes \
  -H 'Content-Type: application/json' \
  --data '{}'

Expected result: HTTP 403.

Use unauthenticated options/set to disable the auth gate:

curl -sS -X POST http://127.0.0.1:5572/options/set \
  -H 'Content-Type: application/json' \
  --data '{"rc":{"NoAuth":true}}'

Expected result: HTTP 200 {}

Then call the same protected method again without credentials:

curl -sS -X POST http://127.0.0.1:5572/config/listremotes \
  -H 'Content-Type: application/json' \
  --data '{}'

Expected result: HTTP…

Summary

The RC endpoint options/set is exposed without AuthRequired: true, but it can mutate global runtime configuration, including the RC option block itself. An unauthenticated attacker can set rc.NoAuth=true, which disables the authorization gate for many RC methods registered with AuthRequired: true on reachable RC servers that are started without global HTTP authentication. This can lead to unauthorized access to sensitive administrative functionality, including configuration and operational RC methods.

Preconditions

Preconditions for this vulnerability are:

• The rclone remote control API must be enabled, either by the --rc flag or by running the rclone rcd server
• The remote control API must be reachable by the attacker - by default rclone only serves the rc to localhost unless the --rc-addr flag is in use
• The rc must have been deployed without global RC HTTP authentication - so not using --rc-user/--rc-pass/--rc-htpasswd/etc

Details

The root cause is present from v1.45 onward. Some higher-impact exploitation paths became available in later releases as additional RC functionality was introduced.

The issue is caused by two properties of the RC implementation:

1. options/set is exposed without AuthRequired: true
2. the RC server enforces authorization for AuthRequired calls using the mutable runtime value s.opt.NoAuth

Relevant code paths:

• fs/rc/config.go

  • registers options/set without AuthRequired: true
  • rcOptionsSet reshapes attacker-controlled input into global option blocks

• fs/rc/rcserver/rcserver.go

  • request handling checks:

    • if !s.opt.NoAuth && call.AuthRequired && !s.server.UsingAuth()

  • once rc.NoAuth is changed to true, later AuthRequired methods become callable without credentials

This creates a runtime auth-bypass primitive on the RC interface.

After setting rc.NoAuth=true, previously protected administrative methods become callable, including configuration and operational endpoints such as:

• config/listremotes
• config/dump
• config/get
• operations/list
• operations/copyfile
• core/command

Relevant code for the second-stage command execution path:

• fs/metadata.go

  • metadataMapper() uses exec.Command(...)

• fs/operations/rc.go

  • operations/copyfile is normally AuthRequired: true
  • once rc.NoAuth=true, it becomes reachable without credentials

This was validating using the following:

• current master as of 2026-04-14: bf55d5e6d37fd86164a87782191f9e1ffcaafa82
• latest public release tested locally: v1.73.4

The issue was also verified on a public amd64 Ubuntu host controlled by the tester, using direct host execution (not containerized PoC execution).

PoC

Minimal reproduction

Start a vulnerable server:

rclone rcd --rc-addr 127.0.0.1:5572

No --rc-user, no --rc-pass, no --rc-htpasswd.

First confirm that a protected RC method is initially blocked:

curl -sS -X POST http://127.0.0.1:5572/config/listremotes \
  -H 'Content-Type: application/json' \
  --data '{}'

Expected result: HTTP 403.

Use unauthenticated options/set to disable the auth gate:

curl -sS -X POST http://127.0.0.1:5572/options/set \
  -H 'Content-Type: application/json' \
  --data '{"rc":{"NoAuth":true}}'

Expected result: HTTP 200 {}

Then call the same protected method again without credentials:

curl -sS -X POST…

Root has patched CVE-2026-41176 in the rootio-github.com/rclone/rclone package for Root:Go. Multiple fixed versions available.

Rclone is a command-line program to sync files and directories to and from different cloud storage providers. The RC endpoint options/set is exposed without AuthRequired: true, but it can mutate global runtime configuration, including the RC option block itself. Starting in version 1.45.0 and prior to version 1.73.5, an unauthenticated attacker can set rc.NoAuth=true, which disables the authorization gate for many RC methods registered with AuthRequired: true on reachable RC servers that are started without global HTTP authentication. This can lead to unauthorized access to sensitive administrative functionality, including configuration and operational RC methods. Version 1.73.5 patches the issue.

Rclone is a command-line program to sync files and directories to and from different cloud storage providers. The RC endpoint options/set is exposed without AuthRequired: true, but it can mutate global runtime configuration, including the RC option block itself. Starting in version 1.45.0 and prior to version 1.73.5, an unauthenticated attacker can set rc.NoAuth=true, which disables the authorization gate for many RC methods registered with AuthRequired: true on reachable RC servers that are started without global HTTP authentication. This can lead to unauthorized access to sensitive administrative functionality, including configuration and operational RC methods. Version 1.73.5 patches the issue.

Rclone: Unauthenticated options/set allows runtime auth bypass, leading to sensitive operations and command execution in github.com/rclone/rclone.

NOTE: The source advisory for this report contains additional versions that could not be automatically mapped to standard Go module versions.

(If this is causing false-positive reports from vulnerability scanners, please suggest an edit to the report.)

The additional affected modules and versions are: .

This update bring new features, bugs and vulnerabilities fixed in rclone and golang components used to build it.

These are all security issues fixed in the rclone-1.73.5-1.1 package on the GA media of openSUSE Tumbleweed.

This update for rclone fixes the following issues:

Changes in rclone:

• Update to version 1.73.5:

  • Version v1.73.5
  • operations: add AuthRequired to operations/fsinfo to prevent backend creation CVE-2026-41179
  • rc: snapshot NoAuth at startup to prevent runtime auth bypass CVE-2026-41176
  • rc: add AuthRequired to options/set to prevent auth bypass CVE-2026-41176
  • s3: fix empty delimiter parameter rejected by Archiware P5 server
  • azureblob/auth: add Microsoft Partner Network User-Agent prefix
  • drime: fix User.EntryPermissions JSON unmarshalling
  • filter: fix debug logs that fire before logger is configured - fixes #9291
  • s3: fix TencentCOS CDN endpoint failing on bucket check
  • iclouddrive: fix 'directory not found' error when the directory contains accent marks
  • Start v1.73.5-DEV development

• Update to version 1.73.4:

  • Version v1.73.4
  • Update to go 1.25.9 to fix multiple CVEs
  • build: fix Denial of Service due to Panic in AWS SDK for Go v2 SDK EventStream Decoder
  • docs: fix markdown issues in mount docs
  • docs: fix header level for metadata option
  • fix(docs): Fix link to not be language specific
  • filen: update SDK version
  • build(deps): bump golang.org/x/image from 0.36.0 to 0.38.0
  • docs: note macOS 10.15 (Catalina) support with version v1.70.3
  • Start v1.73.4-DEV development

• Update to version 1.73.3: (CVE-2026-33186 GHSA-6g7g-w4f8-9c9x)

  • Version v1.73.3
  • build(deps): bump github.com/buger/jsonparser from 1.1.1 to 1.1.2
  • docs/jottacloud: fix broken link
  • docs: clarify Filen password change requires updating both password and API key in rclone config
  • docs: note that Filen API key changes on password change
  • build(deps): bump google.golang.org/grpc from 1.79.1 to 1.79.3
  • s3: add multi tenant support for Cubbit
  • lib/rest: fix URLPathEscapeAll breaking WebDAV servers (eg nzbdav) with strict path matching
  • list: fix nil pointer panic in Sorter when temp file creation fails
  • docs: update RELEASE procedure to avoid mistakes
  • docs: added text to the label showing version-introduced info
  • Start v1.73.3-DEV development
  • docs: update sponsors

• Update to version 1.73.2:

  • Version v1.73.2
  • Update to go 1.25.8 to fix multiple CVEs
  • build: update to golang.org/x/net v0.51.0 to fix CVE-2026-27141 #9220
  • docs: fix new drive flag typo in changelog
  • webdav: add missing headers for CORS
  • docs: Document unsupported S3 object keys with double slashes
  • docs: note that --use-server-modtime only works on some backends
  • internxt: fix Entry doesn't belong in directory errors on windows
  • drime: fix chunk-uploaded files ignoring workspace ID
  • docs: Fix headers hierarchy for mount.md
  • webdav: escape reserved characters in URL path segments
  • bisync: add group Sync to the bisync command
  • archive: extract: strip "./" prefix from tar entry paths
  • docs: add instructions on how to update Go version
  • buid: update github.com/cloudflare/circl to v1.6.3 to fix CVE-2026-1229
  • Start v1.73.2-DEV development

• Update to version 1.73.1:

  • Version v1.73.1
  • build: fix build using go 1.26.0 instead of go 1.25.7
  • fs/march: fix runtime: program exceeds 10000-thread limit
  • accounting: fix missing server side stats from core/stats rc
  • pacer: re-read the sleep time as it may be stale
  • pacer: fix deadlock between pacer token and --max-connections
  • build: fix CVE-2025-68121 by updating go to 1.25.7 or later - fixes #9167
  • drime: fix files and directories being created in the default workspace
  • docs: update sponsors
  • copyurl: Extend copyurl docs with an example of CSV FILENAMEs starting with a path.
  • internxt: implement re-login under refresh logic, improve retry logic - fixes #9174
  • docs: add ExchangeRate-API as a sponsor
  • build: bump github.com/go-chi/chi/v5 from 5.2.3 to 5.2.5 to fix GO-2026-4316
  • Set list_version to 2 for FileLu S3 configuration
  • filelu: add multipart upload support…

This update for rclone fixes the following issues:

Changes in rclone:

• Update to version 1.74.4 (boo#1267192):

  • Version v1.74.4
  • gui: update embedded release to 1.1.10
  • local: stop --links symlinks escaping the destination directory CVE-2026-54572
  • local: don't restore setuid/setgid/sticky bits from metadata by default GHSA-945v-v9p3-v5xw
  • s3: strip STS security token on same-host HTTPS->HTTP redirect GHSA-cf44-9pgv-m4xc
  • serve restic: fix --private-repos isolation bypass CVE-2026-59733
  • archive extract: fix path traversal letting archives escape the destination CVE-2026-59732
  • serve s3: fix path traversal letting clients see files in the root GHSA-8v25-v8p6-qf7v
  • build: fix multiple CVEs by upgrading to go1.26.5
  • s3: fix mounting a prefix failing with 403 when HEAD is not permitted
  • drive, googlephotos: warn when using rclone's shared client_id #9580
  • drive: fix stray %!(EXTRA) in unexportable google document log message
  • serve/http: fix --disable-zip so it works over rc
  • serve webdav: fix MOVE overwrite failing without Overwrite header
  • fs: fix negative offset when a suffix Range request exceeds object size
  • accounting: fix goroutine leak in NewStatsGroup for zero-transfer rc jobs
  • cmd/mount2: fix NFS directory listings by supporting non-zero Seekdir offsets
  • cmd/mount2: fix ESTALE over NFS by reporting stable inode numbers
  • cmd/mount2: fix NFS file creation by implementing Mknod
  • smb: fix for IBM iSeries and signature verification
  • mega: fix hard deleted files reappearing in listings - fixes #9554
  • mega: wait for server events after upload, delete and move
  • vfs: fix hang reopening a file during the handle-caching grace period
  • s3: correct documented copy_cutoff minimum to 1 byte - Fixes #7391
  • fs: fix command line flag being ignored when set to its default value
  • docs: fix copy to clipboard functionality for code blocks
  • fs/operations: correct DeleteFile --backup-dir documentation
  • build: update golang.org/x/image to v0.43.0 to fix image decoding vulnerabilities
  • docs: clarify copyto command description - Fixes #9527
  • docs: fix typo in remote setup docs
  • serve s3: fix spurious 404 on HEAD/GET during VFS writeback - fixes #8188
  • • s3: fix error mapping in GetObject to match HeadObject
  • filter: fix --files-from copy stopping at the first unreadable file
  • docs: Fix RELEASE.md
  • ncdu: fix duplicated keystrokes on Windows by pinning tcell to v2.9.0
  • completion: fix powershell completion corrupting non-ASCII names - fixes #9412
  • docs/crypt: fix encrypted size example - Fixes #9202
  • docs: drive: note Google verification exemption for personal use apps
  • rc: document that rc API access is equivalent to shell access
  • docs: drive: update documentation about "Computers" folder
  • accounting: fix goroutine leak in ResetCounters
  • docs: fix --windows-event-log-level help
  • backend/filelu: fix recursive listing path handling and file filtering
  • docs: bisync - clarify flag interaction and minor changes
  • docs: Update RELEASE.md to use cherry-pick -x
  • webdav: fix mixed property statuses in multi-status responses
  • s3: remove session token on cross-host redirects
  • drive: warn when non-exportable Google documents are skipped - #9475
  • Start v1.74.4-DEV development

• update x/image to 0.43 (bsc#1271056)

• Update to version 1.74.3: (boo#1267869)

  • Bug Fixes
    • rc
      • Fix unauthenticated command execution via --rc-serve inline remotes CVE-2026-49980 (Nick Craig-Wood)
      • Stop global.* connection string options changing config CVE-2026-49980 (Nick Craig-Wood)
    • build: Fix multiple CVEs by upgrading to go1.26.4 (Nick Craig-Wood)
      • CVE-2026-42504: mime: quadratic complexity in WordDecoder.DecodeHeader
      • CVE-2026-42507: net/textproto: arbitrary input are included in errors without any escaping
      • CVE-2026-27145: crypto/x509: split…

This update for govulncheck-vulndb fixes the following issues:

• Update to version 0.0.20260723T184607 2026-07-23T18:46:07Z (jsc#PED-11136).

Go CVE Numbering Authority IDs added or updated with aliases:

• GO-2026-4730 CVE-2026-33022 GHSA-cv4x-93xx-wgfj
• GO-2026-4761 CVE-2026-33211 GHSA-j5q5-j9gm-2w5c
• GO-2026-5102 CVE-2026-45021 GHSA-3vcp-chfh-f6r2
• GO-2026-5272 CVE-2026-40938 GHSA-94jr-7pqp-xhcq
• GO-2026-5486 CVE-2026-40924 GHSA-m2cx-gpqf-qf74
• GO-2026-5542 CVE-2026-40090 GHSA-pj97-4p9w-gx3q
• GO-2026-5630 CVE-2026-25542 GHSA-rmx9-2pp3-xhcr
• GO-2026-5643 CVE-2026-40923 GHSA-rx35-6rhx-7858
• GO-2026-5675 CVE-2026-41492 GHSA-vvf7-6rmr-m29q
• GO-2026-5711 CVE-2026-40161 GHSA-wjxp-xrpv-xpff
• GO-2026-5746 CVE-2026-41567 GHSA-x86f-5xw2-fm2r
• GO-2026-5749 CVE-2026-41328 GHSA-x92x-px7w-4gx4
• GO-2026-5837 CVE-2026-44840 GHSA-q2m9-6jp9-c6mc
• GO-2026-5929 CVE-2026-44342 GHSA-26v7-h57m-gh9m
• GO-2026-5930 CVE-2026-33655 GHSA-6qcr-qxgr-m7fv
• GO-2026-5933 GHSA-3g4q-2f67-2gvh
• GO-2026-5934 GHSA-59qp-cfj3-rp64
• GO-2026-5935 GHSA-7856-g3gv-9wq8
• GO-2026-5936 CVE-2026-53552 GHSA-26rh-24rg-j3vv
• GO-2026-5937 CVE-2026-53508 GHSA-2jcc-mxv7-p3f9
• GO-2026-5938 CVE-2026-53553 GHSA-4g5x-hcwm-82jw
• GO-2026-5939 CVE-2026-10517 GHSA-698x-9w2p-7vvp
• GO-2026-5940 CVE-2026-53572 GHSA-6w3m-4hhp-775q
• GO-2026-5941 CVE-2026-53487 GHSA-gvhc-wv3v-7pf8
• GO-2026-5942 CVE-2026-46600
• GO-2026-5944 CVE-2026-50197 GHSA-659f-rgp5-w4wf
• GO-2026-5945 CVE-2026-6815 GHSA-rmxx-v9rj-vpvg
• GO-2026-5946 CVE-2026-52831 GHSA-v5px-423j-pf7p
• GO-2026-5947 CVE-2026-53649 GHSA-xqhv-chqm-fhcc
• GO-2026-5948 CVE-2026-50554 GHSA-588f-fvcv-xhvf
• GO-2026-5949 CVE-2026-50553 GHSA-rqrh-8wpv-x7hh
• GO-2026-5950 CVE-2026-53602 GHSA-339v-266x-79xr
• GO-2026-5951 CVE-2026-10219 GHSA-6jm8-4fhr-5w64
• GO-2026-5952 CVE-2026-49834 GHSA-9vcr-p3rj-q5q6
• GO-2026-5953 CVE-2026-9094 GHSA-c9w5-qp6m-m395
• GO-2026-5956 CVE-2026-55252 GHSA-h5g6-xmh4-hc37
• GO-2026-5957 CVE-2026-54158 GHSA-5xfx-xj4h-5p7r
• GO-2026-5958 CVE-2026-54068 GHSA-gcm7-57gf-953c
• GO-2026-5959 CVE-2026-54072 GHSA-h29v-hj44-q8cv
• GO-2026-5961 CVE-2026-54069 GHSA-hvr9-72v2-fff3
• GO-2026-5962 CVE-2026-54088 GHSA-m93h-4hw7-5qcm
• GO-2026-5963 CVE-2026-54067 GHSA-mvjr-vv3c-w4qv
• GO-2026-5964 CVE-2026-54066 GHSA-p4m3-mgmm-c664
• GO-2026-5965 CVE-2026-54070 GHSA-w7cg-whh7-xp28
• GO-2026-5966 CVE-2026-54089 GHSA-xqp3-jq6g-x3qm
• GO-2026-5967 CVE-2026-50551 GHSA-56mp-4f3v-fgj2
• GO-2026-5968 CVE-2026-54174 GHSA-fpg8-7664-jc5q
• GO-2026-5969 GHSA-g936-7jqj-mwv8
• GO-2026-5970 CVE-2026-56852
• GO-2026-5973 CVE-2026-54250 GHSA-jxr7-mqhw-9p98
• GO-2026-5974 CVE-2026-44300 GHSA-wmj8-9953-vff5
• GO-2026-5975 CVE-2026-50018 GHSA-42j2-w334-qxw7
• GO-2026-5976 CVE-2026-50141 GHSA-g7mm-9vx7-jm7h
• GO-2026-5977 CVE-2026-50013 GHSA-qrh4-p6v4-mrfg
• GO-2026-5978 CVE-2026-50125 GHSA-qw5r-ppcg-f8rj
• GO-2026-5979 CVE-2026-50006 GHSA-xrcf-6jh3-ggvx
• GO-2026-5980 CVE-2026-50158 GHSA-2c7f-fxww-6w6c
• GO-2026-5981 GHSA-mqxv-9rm6-w8qc
• GO-2026-5982 GHSA-pqg7-v6wh-3pfp
• GO-2026-5984 CVE-2026-53604 GHSA-2p2f-px33-4vv5
• GO-2026-5985 GHSA-7rx3-5wx3-5v76
• GO-2026-5986 CVE-2026-61699 GHSA-cm26-5974-52h8
• GO-2026-5987 CVE-2026-55513 GHSA-g4x6-jcvr-9m3g
• GO-2026-5988 CVE-2026-54628 GHSA-hwrq-8wxh-q4xv
• GO-2026-5989 CVE-2026-55512 GHSA-m3cx-mwpg-32jg
• GO-2026-5990 CVE-2026-54629 GHSA-mf78-3rpf-r784
• GO-2026-5991 CVE-2026-53603 GHSA-q4vm-pq3q-8wgq
• GO-2026-5992 CVE-2026-61549 GHSA-qf34-295c-26v8
• GO-2026-5996 CVE-2026-54450 GHSA-pph6-vfjv-vpjw
• GO-2026-5997 CVE-2026-54452 GHSA-xgch-x3mx-cm3c
• GO-2026-5998 CVE-2026-54495 GHSA-398h-7f66-3h4p
• GO-2026-5999 CVE-2026-10814 GHSA-jh6h-v6mp-h22v
• GO-2026-6002 CVE-2026-58196 GHSA-pr64-jmmf-jp54
• GO-2026-6003 CVE-2026-53714 GHSA-22xc-xg2r-9j7v
• GO-2026-6004 CVE-2026-52833 GHSA-3v79-m2cg-89ww
• GO-2026-6005 CVE-2026-53715 GHSA-8fv2-88gg-hm7q
• GO-2026-6006 CVE-2026-53716 GHSA-cxpq-8v7q-cg56 *…

It was discovered that Rclone incorrectly handled authorization in the remote control API. An attacker could possibly use this issue to obtain sensitive information. (CVE-2026-41176)

It was discovered that Rclone incorrectly handled backend instantiation via the remote control API. An attacker could possibly use this issue to execute arbitrary code. This issue only affected Ubuntu 24.04 LTS, Ubuntu 25.10 and Ubuntu 26.04 LTS. (CVE-2026-41179)