Skip to content
Patch Next
Sign inAdd to your agent

← Actionable
Critical, CVSS 9.9

Rancher Fleet vulnerable to cross namespace secret disclosure via unvalidated valuesFrom references in Helm Deployer

CVE-2026-44935GHSA-xr65-5cpm-g36x

What to do

Vendor fix available. Upgrade each affected package to the fixed version on its release line (github.com/rancher/fleet 0.15.2, 0.14.6, 0.13.11, 0.12.15), redeploy, then verify what is actually installed.

This page has no inventory attached, so it cannot say whether you are affected. A vendor fix is not proof that your deployment is fixed.

Add to your agent

Affected packages

  • Go github.com/rancher/fleet

    Affected
    >= 0.15.0, < 0.15.2>= 0.14.0, < 0.14.6>= 0.13.0, < 0.13.11>= 0.12.0, < 0.12.15
    Fixed in
    0.12.15, 0.14.6, 0.15.2, 0.13.11

Sources

Severity and exploitation
Exploitation
No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.
CVSS
9.9 · CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H
EPSS
  • CVE-2026-44935: 0.49% estimated exploitation activity in the next 30 days; percentile 42.20 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.
Source description

As published by the source; long descriptions are shortened.

Impact A vulnerability in Fleet for Rancher Manager affects multi-tenancy environments where different tenants share the same downstream clusters (e.g., different privileged or untrusted teams inside the same organization). On unpatched versions, tenants could bypass restrictions to access any config map or secret across all namespaces on the downstream cluster. They can create cluster-wide resources using HelmOp or Bundle without authorization. Specifically, an attacker can exploit this vulnerability in the following ways: 1. Use valuesFrom in fleet.yaml(through a GitRepo resource) or a HelmOp resource to read the contents of any secret an on the downstream cluster, provided they know or can guess the name, namespace, and key. 2. Deploy HelmOp and Bundle resources without being restricted to a specific service account for the Fleet agent. If you use Fleet in a multi-tenant environment, it's recommended that you: - Review your cluster and Fleet deployments logs for indicators of…

Dates and revisions
Published by the source
Last modified by the source
Source last checked
  1. Revision 1 · created ·

    Published from ghsa record GHSA-xr65-5cpm-g36x

Agent brief

Preview the exact text before you copy it. Commands are read-only suggestions; review them before running anything.

# Patch Next advisory brief: CVE-2026-44935

Advisory: Rancher Fleet vulnerable to cross namespace secret disclosure via unvalidated `valuesFrom` references in Helm Deployer
IDs: CVE-2026-44935, GHSA-xr65-5cpm-g36x
Record: https://patchnext.com/advisories/cve-2026-44935 (revision 1, source checked 26 Oct 2026, 15:24 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: Critical (CVSS 9.9)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: github.com/rancher/fleet 0.15.2, 0.14.6, 0.13.11, 0.12.15. A vendor fix does not mean a deployment is fixed.

## Affected components
- Go github.com/rancher/fleet: affected >= 0.15.0, < 0.15.2; >= 0.14.0, < 0.14.6; >= 0.13.0, < 0.13.11; >= 0.12.0, < 0.12.15; fixed in 0.12.15, 0.14.6, 0.15.2, 0.13.11

## Suggested inspection (read-only)
- Go github.com/rancher/fleet: check the installed version with your package manager.

## Supported action
Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on github.com/rancher/fleet.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://github.com/advisories/GHSA-xr65-5cpm-g36x (GitHub-reviewed advisory GHSA-xr65-5cpm-g36x lists affected ranges: Go github.com/rancher/fleet >=0.15.0 =0.14.0 =0.13.0 =0.12.0 <0.12.15)

Commands are suggestions: review each one before running it.

Loading voting…