CVE-2026-79783 rclone CVE debrief

Who should care

Defenders responsible for systems using rclone, especially those using untrusted remote sources, should assess exposure and consider upgrading to rclone 1.74.4 or later. This includes operators, platform administrators, vulnerability management teams, and security teams who need to verify rclone configurations and ensure security.

Why it matters

Defenders should care about CVE-2026-79783 because it allows attackers to potentially escalate privileges or plant setuid binaries when using rclone with untrusted remote sources.

• Potential privilege escalation to root or service account user
• Possible planting of setuid binaries
• Verification of rclone versions and configurations required

Technical summary

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. This vulnerability can lead to potential privilege escalation if rclone runs as root or to the service account user. The issue arises when copying with metadata preservation from an untrusted remote, enabling attackers to plant a setuid binary. Technical details indicate a need for defenders to verify rclone versions and configurations.

Defensive priority

Defenders should prioritize verifying rclone versions and configurations, especially where untrusted remote sources are used.

Recommended defensive actions

• Verify rclone version and configuration
• Assess exposure to untrusted remote sources
• Consider upgrading to rclone 1.74.4 or later
• Review compensating controls for exposed systems
• Check relevant monitoring, detection, and logs for exposed assets
• Track exceptions, retest remediated assets
• Confirm whether affected product deployments exist in managed environments

Evidence notes

The CVE record and NVD entry provide details on the vulnerability, but additional verification is needed to confirm affected versions and remediation. Evidence from the CVE Program and NVD suggests that rclone's failure to mask special permission bits can lead to security risks. Further review of rclone configurations and version verification is necessary to ensure security.

Sources and references

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.