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KyvernoApplication

CVE-2026-4789

CRITICAL · 9.8 CVSS v3.1 Published 2026-03-30
Fix available
A fix is available. Upgrade to after 1.17.1 or later.
See remediation →
100/100
Remediation priority · Urgent
Remotely reachable No privileges Zero-click

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
Kyverno, versions 1.16.0 and later, are vulnerable to SSRF due to unrestricted CEL HTTP functions.

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

Kyverno versions 1.16.0 and later contain a Server-Side Request Forgery (SSRF) vulnerability stemming from unrestricted CEL (Common Expression Language) HTTP functions. This allows attackers to potentially make the Kyverno server perform arbitrary HTTP requests to internal or external resources, potentially exposing sensitive services or facilitating further attacks.

MitigationImplement network segmentation and egress controls to limit which destinations Kyverno can reach; additionally, configure URL allowlisting for CEL HTTP functions and consider upgrading once a vendor patch is available.

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

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
KyvernoApplication
Affected:>= 1.16.0, <= 1.17.1

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
None
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

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

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. Identify installed Kyverno version
    Run 'kubectl get deploy -n kyverno kyverno -o jsonpath="{.spec.template.spec.containers[0].image}"' or check the Kyverno service account version. Alternatively, query the Kyverno metrics endpoint or check the Helm chart values.
    Affected if The returned version is between 1.16.0 and 1.17.1 inclusive (for example, 1.16.0, 1.16.1, 1.17.0, 1.17.1).
  2. Check for policies using CEL HTTP functions
    Review all ClusterPolicy and Policy resources in the cluster: 'kubectl get clusterpolicy -o yaml' and 'kubectl get policy -A -o yaml'. Search for 'http.' or ' CEL' or expressions containing HTTP calls within the policy definitions.
    Affected if Any policy contains CEL expressions that make HTTP requests (for example, 'http.get', 'http.post', or similar HTTP function calls in validate rules or context variables).
  3. Inspect Kyverno admission controller logs for HTTP requests
    Retrieve logs from the Kyverno controller pods: 'kubectl logs -n kyverno -l app=kyverno --tail=500'. Search for patterns indicating outbound HTTP activity, especially to internal IPs or non-public domains.
    Affected if Logs show HTTP requests initiated by Kyverno to arbitrary internal or external URLs that were not explicitly expected or configured for legitimate policy operations.
  4. Review CEL HTTP function configuration
    Check the Kyverno deployment or Helm values for any explicit CEL-related configuration: 'kubectl get deploy -n kyverno kyverno -o yaml' and examine environment variables or flags related to CEL validation or HTTP function handling.
    Affected if CEL HTTP functions are permitted or not explicitly disabled, and Kyverno is running an affected version.

A user is affected if Kyverno version is between 1.16.0 and 1.17.1 AND CEL HTTP functions are in use through policies or enabled by default, allowing potential SSRF attacks.

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
Upgrade available Upgrade to a release after 1.17.1
Interim mitigation

Implement network segmentation and egress controls to limit which destinations Kyverno can reach; additionally, configure URL allowlisting for CEL HTTP functions and consider upgrading once a vendor patch is available.

Recommended fix Moderate confidence

Kyverno 1.17.2 or later (latest stable release)

  1. Identify your current Kyverno version using 'kubectl get deployment -n kyverno kyverno -o jsonpath='{.spec.template.spec.containers[0].image}''
  2. Review the Kyverno releases page (github.com/kyverno/kyverno/releases) for versions newer than 1.17.1 that contain the SSRF fix for CEL HTTP functions
  3. Upgrade Kyverno to version 1.17.2 or later (or the latest stable release)
  4. After upgrade, verify the new version is running: 'kubectl get deployment -n kyverno kyverno -o jsonpath='{.spec.template.spec.containers[0].image}''
  5. Test that policy enforcement continues to function correctly with your existing policies
  6. If upgrading is not immediately possible, consider restricting network access to the Kyverno admission controller and implementing network policies to limit outbound connections from the Kyverno namespace
Caveat Review release notes for any breaking changes between your current version and the target version; test in non-production first

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

Fix this in Kyverno Scoped from the published advisory
  • Consultation4.0 h
  • Implementation8.0 h
  • Testing6.0 h
  • Review / QA3.0 h
21.0 hours of engineering $3,680
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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-2026-4789 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