# CVE-2026-79783: rclone local backend privilege escalation via setuid metadata

Source: https://junglewise.ai/threats/cve-2026-79783-rclone-local-backend-privilege-escalation-via-setuid-metadata  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-08-25. Updated: 2026-09-25  
License: CC BY 4.0 with a link back

CVE-2026-79783 · Severity: low · CVSS 3.6 · Published 2026-08-25

rclone is a command-line tool for syncing files to and from cloud storage and local filesystems. When copying files with metadata preservation from an untrusted remote, an attacker can supply specially crafted file permissions that cause rclone to create setuid binaries. If rclone runs as root (common for backup and restore operations), this allows any local user to gain root access; if running as a service account, it enables privilege escalation to that account.

Technologies: [github.com/rclone/rclone (Go)](https://junglewise.ai/threats/technologies/github-com-rclone-rclone), [Rclone](https://junglewise.ai/threats/technologies/rclone). Vendors: [Go](https://junglewise.ai/threats/vendors/go), [Rclone](https://junglewise.ai/threats/vendors/rclone).

## Quick answers

**Is CVE-2026-79783 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-79783 being exploited in the wild.

**How severe is CVE-2026-79783?** Low severity, with a CVSS score of 3.6, published 25 August 2026.

**Which products and versions are affected?** github.com/rclone/rclone (Go) SEMVER:introduced=0,fixed=1.74.4; Rclone before 1.74.4.

**Is there a fix for CVE-2026-79783?** Yes. github.com/rclone/rclone (Go): upgrade to 1.74.4 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-79783 attacked?** It is attacked with local access.

**Am I affected by CVE-2026-79783?** Check whether you run github.com/rclone/rclone (Go) or Rclone at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## How to fix

- github.com/rclone/rclone (Go): upgrade to 1.74.4 or later

  ```sh
  go get github.com/rclone/rclone@v1.74.4
  ```


## Technical details

The vulnerability exists in rclone's local backend metadata handling (backend/local/metadata.go, writeMetadataToFile). When applying mode metadata from the source, the code parses the mode value and passes it directly to os.Chmod() without masking special permission bits (setuid, setgid, sticky). An attacker can supply a mode value such as 40000755 (Go FileMode layout with setuid bit set) along with uid=0 to create a root-owned setuid binary with attacker-controlled content. The attack requires the victim to run rclone with the -M (metadata preservation) flag on an attacker-controlled or compromised remote. The fix masks permission bits before applying them and gates uid/gid/setuid application behind an off-by-default opt-in flag.

## Affected products

- rclone rclone before 1.74.4

## Identifiers

- CVE-2026-79783
- GHSA-945v-v9p3-v5xw
- GO-2026-6190

## Timeline

- 2026-07-08: disclosed
- 2026-08-25: advisory
- 2026-08-25: patched: version 1.74.4

## References

- [https://github.com/rclone/rclone/security/advisories/GHSA-945v-v9p3-v5xw](https://github.com/rclone/rclone/security/advisories/GHSA-945v-v9p3-v5xw)
- [https://www.vulncheck.com/advisories/rclone-before-privilege-escalation-via-setuid-metadata](https://www.vulncheck.com/advisories/rclone-before-privilege-escalation-via-setuid-metadata)

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