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Missing AuthenticationWeakness · CWE-306

CVE-2026-44949

HIGH · 7.0 CVSS v4.0 Published 2026-06-30
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
76/100
Remediation priority · High
Remotely reachable Zero-click 8 weeks old

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
A Rancher FleetWorkspace admission path allowed side effects to occur in the Rancher webhook handler for versions 0.7.0 up to 0.7.10, 0.8.0 up to 0.8.7, 0.9.0 up to 0.9.6 and 0.10.0 up to 0.10.7. An unauthenticated attacker with network access to the in-cluster rancher-webhook service could submit a crafted admission payload and cause workspace-related Kubernetes objects to be created with attacker-chosen identity data.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · moderate confidence

A Rancher FleetWorkspace admission webhook path in rancher-webhook versions 0.7.0-0.7.10, 0.8.0-0.8.7, 0.9.0-0.9.6, and 0.10.0-0.10.7 allows side effects to occur, permitting unauthenticated attackers with network access to submit crafted admission payloads that create workspace-related Kubernetes objects with attacker-controlled identity data.

MitigationUpgrade rancher-webhook to versions 0.7.11, 0.8.8, 0.9.7, or 0.10.8 and later; additionally, restrict network access to the in-cluster rancher-webhook service to limit attack surface.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Network
Complexity
Low
Privileges
Low
Authentication
X
User interaction
None
Scope
X

CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:N/VI:H/VA:N/SC:N/SI:H/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Find the rancher-webhook deployment
    Run 'kubectl get deployments -n cattle-system' or 'kubectl get pods -n cattle-system | grep webhook' to locate the rancher-webhook pod/deployment
    Affected if No rancher-webhook deployment exists in the cattle-system namespace (not affected)
  2. Determine the installed rancher-webhook version
    Run 'kubectl get deployment rancher-webhook -n cattle-system -o jsonpath="{.spec.template.spec.containers[0].image}"' to get the image, then compare the version tag against the affected ranges: 0.7.0-0.7.10, 0.8.0-0.8.7, 0.9.0-0.9.6, or 0.10.0-0.10.7
    Affected if The version falls within any of the four affected ranges (0.7.x, 0.8.x, 0.9.x, or 0.10.x up to the patched versions)
  3. Verify the FleetWorkspace admission webhook exists
    Run 'kubectl get validatingwebhookconfigurations | grep -i fleet' and 'kubectl get mutatingwebhookconfigurations | grep -i fleet' to check for FleetWorkspace webhook configurations
    Affected if No FleetWorkspace webhook configuration is found (not affected, or webhook not in use)
  4. Confirm network exposure of the webhook service
    Check if the rancher-webhook service is exposed externally by reviewing service definitions 'kubectl get svc rancher-webhook -n cattle-system' and cluster network policies; the vulnerability requires network access to the webhook endpoint
    Affected if The rancher-webhook service is accessible from outside the cluster or from untrusted networks (combined with vulnerable version, this enables exploitation)

You are affected if rancher-webhook is running a version between 0.7.0-0.7.10, 0.8.0-0.8.7, 0.9.0-0.9.6, or 0.10.0-0.10.7 AND the FleetWorkspace admission webhook is configured AND the webhook is network-accessible to unauthenticated attackers.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

dbcve · scoped
Mitigation available No clean upgrade yet — mitigate in the meantime
Mitigation

Upgrade rancher-webhook to versions 0.7.11, 0.8.8, 0.9.7, or 0.10.8 and later; additionally, restrict network access to the in-cluster rancher-webhook service to limit attack surface.

Recommended fix Moderate confidence

0.7.11, 0.8.8, 0.9.7, or 0.10.8 depending on your current branch (first version after your affected range)

  1. Identify the currently deployed Rancher Fleet version by checking the rancher-fleet-system namespace or the Helm release
  2. Determine which version range your current deployment falls into (0.7.x, 0.8.x, 0.9.x, or 0.10.x)
  3. Upgrade Rancher Fleet to the first version beyond your affected range: for 0.7.x go to 0.7.11, for 0.8.x go to 0.8.8, for 0.9.x go to 0.9.7, for 0.10.x go to 0.10.8
  4. After upgrade, verify the rancher-webhook pod is running correctly in the cattle-system namespace
  5. Test that admission webhooks are functioning by creating a test FleetWorkspace and confirming proper validation occurs

Generated from the published advisory — verify against the referenced sources before acting.

Have this fixed Scoped from the published advisory
  • Consultation4.0 h
  • Implementation4.0 h
  • Testing8.0 h
  • Review / QA4.0 h
20.0 hours of engineering $3,440
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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2026-44949 in production — separate from our analysis above.

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What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
  • No weaponised exploit code, or anything meant to cause harm
  • No spam, self-promotion, credentials, or personal data