rclone: Missing Authentication for Critical Functionality
CVE-2026-41176 is a critical-severity missing authentication for critical functionality vulnerability in rclone, with a CVSS 3.1 base score of 9.8 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. Affected rclone versions: >= 1.45.0, < 1.73.5. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 32.7% chance of exploitation within 30 days, which is in the top 1.63% of all scored CVEs.
Critical severity: a successful attack would have severe impact.
What to do
- Check which version of rclone you run against the affected versions below, and install the vendor's latest release.
- Read the advisory on github.com for workarounds and exact fixed builds.
- Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Rclone | rclone | >= 1.45.0, < 1.73.5 | Not stated |
| Red Hat | OpenShift API for Data Protection | Not specified in the record | Not stated |
| Red Hat | Red Hat Advanced Cluster Management for Kubernetes 2 | Not specified in the record | Not stated |
Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.
How the severity score breaks down
- Attack vector
- NetworkCan be exploited remotely over a network, including the internet.
- Attack complexity
- LowNo special conditions are needed; the attack works reliably.
- Privileges required
- NoneNo account or login is needed.
- User interaction
- NoneNo action by a victim is required.
- Scope
- UnchangedImpact stays within the vulnerable component.
- Confidentiality
- HighAll data handled by the component can be read.
- Integrity
- HighData or code can be modified at will.
- Availability
- HighThe component can be taken down completely.
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H. Scored by NVD.
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 4.0 | 9.2 | Critical | CNA (github.com) |
| CVSS 3.1 | 9.8 | Critical | NVD |
| CVSS 3.1 | 9.8 | Critical | CNA |
Official description
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.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Missing Authentication for Critical Functionality
The product does not perform any authentication for functionality that requires a provable user identity or consumes a significant amount of resources.
How developers prevent this class of flaw
- For any security checks that are performed on the client side, ensure that these checks are duplicated on the server side, in order to avoid CWE-602. Attackers can bypass the client-side checks by modifying values after the checks have been performed, or by changing the client to remove the client-side checks entirely. Then, these modified values would be submitted to the server.
- Use a vetted library or framework that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid. For example, consider using libraries with authentication capabilities such as OpenSSL or the ESAPI Authenticator.
- When storing data in the cloud (e.g., S3 buckets, Azure blobs, Google Cloud Storage, etc.), use the provider's controls to require strong authentication for users who should be allowed to access the data.
More Missing Authentication for Critical Functionality vulnerabilities (CWE-306)
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: poc, automatable: yes, technical impact: total).
- Record last changed materially (score, affected products, status or references).
References
Advisories
Other references
- github.com/rclone/rclone/blob/bf55d5e6d37fd86164a87782191f9e1ffcaafa82/fs/rc/config.goProduct
- github.com/rclone/rclone/blob/bf55d5e6d37fd86164a87782191f9e1ffcaafa82/fs/rc/rcserver/rcserver.goProduct
- access.redhat.com/security/cve/CVE-2026-41176
- bugzilla.redhat.com/show_bug.cgi?id=2460989
- security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-41176.json
Other vulnerabilities in rclone
- 7.5 High severity
- 7.5 High severity
- 7.5 High severity
- 9.1 Critical severity
- 9.8 Critical severity
- 7.3 High severity
Recent Missing Authentication for Critical Functionality vulnerabilities
- 8.7 High severity
- 8.2 High severity
- 9.8 Critical severity
- 8.7 High severity
- 9.1 Critical severity
- 9.1 Critical severity
Spotted an error? Tell us.