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.
Written by anthropic/claude-haiku-5.5 from the sources below. Verify against them.
- Exploited
- No known exploitation
- Fix
- Fixed in 1.19.2
- Who is exposed
- Specific setups only
Do first: Check whether your setup matches what the bug needs. Kyverno version 1.19.1 up to but not including 1.19.2 A namespaced Policy using an apiCall context Attacker is a namespace tenant with create permission on policies in its own namespace
- Last modified
- A 0-100 score for how much a CVE matters across the industry: exploitation, exposure, how widely the software is used, severity and whether a fix exists.What do these mean? →
- 17/100 · provisional
- How many real-world setups can hit the bug, from the vendor's advisory and CISA data. It does not know your setup.What do these mean? →
- Specific setups only
- Whether working attack code is public (Exploit-DB, Metasploit, Nuclei or GitHub). Public code makes attacks easier.What do these mean? →
- None on Exploit-DB, Metasploit or GitHub
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.
Read the original 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.
cve.now Index
- Exploitation?/40Unknown. No CISA SSVC exploitation rating yet
- Exposure8/25Specific setups only, reachable over the network
- Reach?/20Unknown. No tracked technology or package matched
- Severity9.4/10CVSS 9.4
- No patch0/5No signal
What would change the score
- Would score about 67 if added to CISA KEV
- Would score about 62 if CISA's SSVC rates exploitation active
- Would score about 24 if CISA's SSVC rates it automatable
What to do
Check whether your setup matches what the bug needs.
Kyverno version 1.19.1 up to but not including 1.19.2 A namespaced Policy using an apiCall context Attacker is a namespace tenant with create permission on policies in its own namespaceUpgrade to a fixed version: 1.19.2.
Timeline
- CVE published
- First seen by cve.now
- Posted on X by cve.now
Affected versions
- kyverno kyverno
From 1.19.1 · fixed in 1.19.2
Evidence 2
- Advisory
- Link
Corrections
None so far.
Something wrong on this page? Report an error. Every fix is listed here.
Questions about CVE-2026-124440
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: cve.now feed data
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: vulncheck.com, github.com
Which versions are affected by CVE-2026-124440?
kyverno: from 1.19.1 before 1.19.2.Source: cve.now feed data
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: vulncheck.com, github.com
How do I fix CVE-2026-124440?
Upgrade Kyverno to version 1.19.2 or later, which contains the fix.Source: vulncheck.com, github.com