What is the CVSS score of CVE-2026-25705?

CVE-2026-25705 has a CVSS 3.1 base score of 8.4 (High). CVSS vector: CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:C/C:H/I:H/A:H. EPSS exploitation probability: 0.0%.

Which versions of Rancher are affected by CVE-2026-25705?

Rancher versions 2.10.11 through 2.14.0 contain a path traversal vulnerability in the UI Extensions mechanism that permits authenticated administrators to write arbitrary files to the server…. A patch is available.

How to fix or mitigate CVE-2026-25705?

Within 24 hours: inventory all Rancher deployments and identify versions 2.10.11-2.14.0; confirm admin user access logs for extension installation activity. Within 7 days: apply vendor-released patches (Rancher 2.11.13, 2.12.9, 2.13.5, or 2.14.1 depending on current version) across all affected clusters; validate patches in non-production environments first. Within 30 days: conduct post-patch security audit of /var/lib/rancher/ directories on affected nodes; review and restrict administrative privileges to principle of least privilege; implement audit logging for UI extension installations.

Rancher CVE-2026-25705

HIGH

Path Traversal: '.../...//' (CWE-35)

2026-05-07 https://github.com/rancher/rancher

GHSA-5v3h-x4wf-5c35

Path Traversal Suse

8.4

CVSS 3.1 · GitHub Advisory

Severity by source

GitHub Advisory PRIMARY

8.4 HIGH

AV:N/AC:L/PR:H/UI:R/S:C/C:H/I:H/A:H

SUSE

HIGH

qualitative

Primary rating from GitHub Advisory.

CVSS VectorGitHub Advisory

CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:C/C:H/I:H/A:H

Attack Vector

Network

Attack Complexity

Low

Privileges Required

High

User Interaction

Required

Scope

Changed

Confidentiality

High

Integrity

High

Availability

High

Lifecycle Timeline

Source Code Evidence Fetched

May 07, 2026 - 01:45 vuln.today

Analysis Generated

May 07, 2026 - 01:45 vuln.today

CVE Published

May 07, 2026 - 01:23 nvd

HIGH 8.4

DescriptionGitHub Advisory

Impact

A vulnerability has been identified in Rancher's Extensions where malicious code can be injected in Rancher through a path traversal in the compressedEndpoint field inside a UIPlugin deployment. A malicious UI extension could abuse that to:

Overwrite Rancher binaries or configuration to inject code.
Write to /var/lib/rancher/ to tamper with cluster state.
If hostPath volumes are mounted, write to the host node filesystem.
Use this issue to chain with other attack vectors.

By default only the administrator can deploy UI extensions, unless permissions are granted to other users. It's always recommended to only install extensions that come from sources trusted by the user.

Please consult the associated MITRE CAPEC-126 - Technique - Path Traversal for further information about this category of attack.

Patches

This vulnerability is addressed by ensuring that:

The file defined by the UI Plugin CR's compressedEndpoint has to be created inside the cache directory and cannot contain ../. If that is not possible, the installation will fail and the file won't be created.
The icons referenced by Cluster Repos' index.yaml file always resolves to a file inside the repository directory.

Patched versions of Rancher include releases v2.14.1, v2.13.5, v2.12.9, v2.11.13.

Workarounds

There is no workaround. The user must be careful about which UI Plugins they install.

Resources

If there are any questions or comments about this advisory:

Reach out to the SUSE Rancher Security team for security related inquiries.
Open an issue in the Rancher repository.
Verify with the support matrix and product support lifecycle.

AnalysisAI

Path traversal in Rancher's UI Extensions mechanism allows authenticated administrators to write arbitrary files to the Rancher server filesystem, potentially overwriting binaries, tampering with cluster state in /var/lib/rancher/, or compromising the host node if hostPath volumes are mounted. This affects Rancher versions 2.10.11 through 2.14.0. While exploitation requires high privileges (administrator access by default) and user interaction to install a malicious extension, the changed scope (S:C) in CVSS 3.1 indicates potential container escape or cross-component impact. Vendor-released patches are available across all affected release branches (2.11.13, 2.12.9, 2.13.5, 2.14.1). No public exploit identified at time of analysis, though the attack technique (CAPEC-126 path traversal) is well-documented.

Technical ContextAI

This vulnerability exploits CWE-35 (Path Traversal) in Rancher's UI Plugin extension system, specifically through the compressedEndpoint field in UIPlugin custom resource deployments. Rancher Extensions allow administrators to add functionality to the Rancher web UI via containerized plugins. The flaw allows path traversal sequences (../) in the compressedEndpoint parameter, causing the plugin installer to write files outside the intended cache directory. The underlying issue is insufficient input validation and path canonicalization before file operations. Affected packages are identified as pkg:go/github.com/rancher/rancher across the 2.11.x through 2.14.x release series. The CVSS vector indicates network-accessible exploitation (AV:N) with low complexity (AC:L) but requires high privileges (PR:H) and user interaction (UI:R), while scope change (S:C) suggests the vulnerability can affect resources beyond the vulnerable component's authorization scope, consistent with potential container escape or host filesystem access.

RemediationAI

Upgrade to patched Rancher releases: version 2.14.1 for the 2.14.x branch, version 2.13.5 for 2.13.x deployments, version 2.12.9 for 2.12.x environments, or version 2.11.13 for 2.11.x installations. The patches implement strict validation ensuring compressedEndpoint paths must resolve within the cache directory and cannot contain ../ traversal sequences, failing installation attempts that violate these constraints. Additionally, icon references in Cluster Repos' index.yaml files are now validated to resolve only within the repository directory. The vendor explicitly states there is no technical workaround for unpatched systems. Compensating controls for organizations unable to immediately patch include: restrict UI Plugin deployment permissions exclusively to highly trusted administrators through Rancher RBAC policies (verify no custom roles grant extension installation rights), implement mandatory security review processes for all UI extensions before deployment with code inspection for suspicious path operations, audit existing installed UI Plugins for legitimacy and remove any from untrusted sources, and monitor /var/lib/rancher/ and Rancher binary directories for unexpected file modifications. These controls reduce but do not eliminate risk, as a compromised or malicious administrator could still exploit the vulnerability. Consult the SUSE Rancher Security team at https://github.com/rancher/rancher/security/policy for environment-specific guidance. Note that restriction of extension deployment effectively limits Rancher's extensibility features until patching is complete.