Rancher: Missing Authentication for Critical Functionality
CVE-2026-88810 is a high-severity missing authentication for critical functionality vulnerability in Rancher from SUSE, with a CVSS 3.1 base score of 7.2 out of 10. It can be exploited remotely over the network by an attacker with administrator privileges, without any action from a user. The record lists versions 2.15.3, 0.11.4, 0.12.1 as the first without the flaw, so updating Rancher to one of those releases or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 0.48% chance of exploitation within 30 days, which is low compared with other CVEs.
High severity with no evidence of exploitation so far.
What to do
- Update Rancher to 2.15.3 or 0.11.4 or 0.12.1, whichever matches your release line, or a later version.
- Read the advisory on github.com for workarounds and exact fixed builds.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| SUSE | Rancher | 2.15.2 up to, but not including, 2.15.3; 0.11.0 up to, but not including, 0.11.4; 0.12.0 up to, but not including, 0.12.1 | 2.15.3, 0.11.4, 0.12.1 |
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
- HighAdministrator-level access is required first.
- 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:H/UI:N/S:U/C:H/I:H/A:H. Scored by CNA (suse.de).
Official description
A privilege escalation issue was discovered in Rancher Manager's role-based access control. The inheritedNamespacedRules field of a GlobalRole propagates permissions into named namespaces of every downstream cluster managed by the Rancher instance, but it was not subject to the privilege-escalation validation applied to the other permission-carrying fields of a GlobalRole. As a result, a non-administrative user could be granted, through a global role binding, permissions in downstream clusters that exceed the permissions that user already holds. This affected SUSE Rancher 2.15.2 only, and SUSE Rancher Webhook 0.11.0 up to 0.11.4, and 0.12.0 up to 0.12.1.
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: none, automatable: no, technical impact: total).
- Record last changed materially (score, affected products, status or references).
References
Other vulnerabilities in Rancher
- 9.1 Critical severity
- 9.1 Critical severity
- 7.6 High severity
- 7.9 High severity
- 8.5 High severity
- 8.8 High severity
Recent Missing Authentication for Critical Functionality vulnerabilities
- 7.5 High severity
- 7.8 High severity
- 9.4 Critical severity
- 7.3 High severity
- 8.7 High severity
- 9.8 Critical severity
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