External risk intelligence

Kyverno Privilege Escalation via Policy API Call URL Path.

CVE advisorySeverity: CRITICAL (CVSS 9.4)

CVE-2026-122310

Kyverno is a Kubernetes-native policy engine that operates exclusively within the internal cluster control plane. The vulnerable functionality requires an authenticated user with permission to create or update policies within the cluster. It is not an internet-facing service, edge gateway, or public-facing application, making it unreachable from the public internet in typical deployments.

Halo Surface Signal: 1 out of 5 — much less likely to be public-facing.

External exposure likelihood

Horizon Alert

Summary of the vulnerability and why it matters

A vulnerability has been identified in Kyverno, a technology used for managing policies in Kubernetes environments. This issue could allow a user with limited permissions to gain administrative access to the entire cluster. The main concern is confirming if our environment utilizes this specific software and, if so, understanding the potential scope of exposure.

Unsanitized URL paths allow privilege escalation.
It allows unauthorized admin access to Kubernetes.
Confirm relevance and assess potential exposure.

Attack Path

How an attacker could exploit the issue

An attacker with the ability to create policies in a specific namespace can manipulate the `context.apiCall.urlPath` field within a Kyverno Policy to bypass intended path cleaning. By strategically embedding segments like `../` after a `#` or `?`, the attacker can trick the Kubernetes client into executing a raw path that leads to cluster-scoped endpoints. This allows the attacker to leverage Kyverno's ServiceAccount to escalate their privileges to cluster administrator level.

Requires authenticated namespace user.
Triggered by crafting a malicious policy path.
Risk of full cluster compromise.

Live Threat

Current exploitation, exposure, and threat context

A namespace-scoped user could potentially gain cluster administrator privileges by crafting a Policy's `context.apiCall` URL path to bypass Kyverno's validation and execute raw path segments. This could allow them to access cluster-scoped endpoints using Kyverno's ServiceAccount when supported by the advisory.

Cluster-scoped endpoints are at risk.
Manipulated URL path bypasses validation.
Attains cluster administrator privileges.

Operational Fix

Recommended remediation, mitigation, and detection steps

Platform and security teams are likely responsible for addressing this vulnerability, which could allow a namespace-scoped user to escalate privileges to cluster administrator. The first practical move is to identify all Kyverno deployments, confirm their reachability and criticality, and then assign ownership for remediation planning.

Platform or security team ownership.
Verify Kyverno deployment reachability.
Plan risk-based remediation actions.

Supplementary metadata

CVSS vector

Validate whether this threat affects your internet-facing exposure.

Halo Threat Intelligence helps prioritize remediation with Halo Surface Signal and H/A/L/O context. Start exposure validation with a free external attack surface trial.

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Frequently asked questions

What is Kyverno and how is it used?

Kyverno is a Kubernetes-native policy engine that acts as an admission controller. It allows administrators to enforce, validate, mutate, and generate configurations for cluster resources automatically. It helps maintain security standards and compliance by managing how applications and infrastructure behave within a cluster environment.

What is the vulnerability in CVE-2026-122310?

This vulnerability is classified as CWE-436, or Interpretation Conflict. It occurs because Kyverno cleans a URL path but later uses the raw path for API calls. An attacker can hide unauthorized navigation segments behind URL fragments or queries, tricking the system into accessing sensitive cluster-wide endpoints that should be off-limits.

How can an attacker trigger this CVE-2026-122310 flaw?

An attacker must have existing permissions to create or update policies within a namespace. They trigger the flaw by embedding forbidden path segments, like '..', after a '#' or '?' character within the 'context.apiCall.urlPath' field. Simply interacting with the cluster normally or having read-only access does not trigger this issue.

Do I need to worry about this if my cluster is internal?

Yes, but the risk profile is different. According to Halo Surface Signal, Kyverno operates within the internal control plane and is not an internet-facing service. While remote attackers cannot reach it directly, any internal user with namespace-level policy creation rights could potentially exploit this to achieve full cluster-wide administrative control.

What should I do first to respond to CVE-2026-122310?

First, audit your environment to identify all active Kyverno deployments and verify their current version. Since this issue is addressed in version 1.19.2, confirm if you are running version 1.19.1. Once verified, coordinate with your platform or security team to plan an upgrade, prioritizing clusters where users have policy-creation permissions.

References

Written by Nicholas Merritt

Nicholas Merritt is VP of Security Solutions at Halo Security. With more than 25 years across application security, vulnerability prioritization, and offensive security, he helps teams translate threat data into practical exposure validation and remediation focus. He authors Halo Threat Intelligence CVE advisories using Halo Surface Signal and H/A/L/O context to prioritize internet-facing risk.