Kyverno 1.17.0 before 1.19.2 Cross-Namespace Write via NamespacedMutatingPolicy mutateExisting
Only affects Kyverno 1.17.0 before 1.19.2 where NamespacedMutatingPolicy uses mutateExisting and tenants can create those policies in their own namespace. 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 1.17.0 up to before 1.19.2 (affected versions up to v1.18.2) A NamespacedMutatingPolicy is used with spec.evaluation.mutateExisting enabled The attacker is a tenant permitted to create a NamespacedMutatingPolicy in their own namespace
- Last modified
- FIRST's estimate of the chance attackers exploit it in the next 30 days, updated daily.What do these mean? →
- 0.17% · 6th percentile
- 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? →
- 16/100 · 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, from 1.17.0 before 1.19.2 has a missing authorization flaw in its mutate-existing background processor. A user with low-privilege access over the network, such as a namespaced tenant, can create a NamespacedMutatingPolicy that modifies resources outside their own namespace, including stripping Pod Security labels cluster-wide.
Read the original description
Kyverno from 1.17.0 before 1.19.2 contains a missing authorization vulnerability in the mutate-existing background processor that allows namespaced tenants to modify resources outside their namespace. Attackers can create a NamespacedMutatingPolicy targeting Namespace objects or victim-namespace resources via CEL expressions, making the background-controller ServiceAccount strip Pod Security labels cluster-wide.
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
- Severity8.4/10CVSS 8.4
- No patch0/5No signal
What would change the score
- Would score about 66 if added to CISA KEV
- Would score about 61 if CISA's SSVC rates exploitation active
- Would score about 23 if CISA's SSVC rates it automatable
What to do
Check whether your setup matches what the bug needs.
Kyverno version 1.17.0 up to before 1.19.2 (affected versions up to v1.18.2) A NamespacedMutatingPolicy is used with spec.evaluation.mutateExisting enabled The attacker is a tenant permitted to create a NamespacedMutatingPolicy in their own namespaceUpgrade to a fixed version: 1.19.2.
Timeline
- CVE published
- First seen by cve.now
Affected versions
- kyverno kyverno
From 1.17.0 · 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-2026-122316
Is CVE-2026-122316 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 tenant permitted to create a NamespacedMutatingPolicy in their own namespace can use mutateExisting to overwrite resources in other namespaces and cluster-scoped Namespace objects. The writes run under Kyverno's background-controller ServiceAccount, and they can strip Pod Security labels cluster-wide.Source: vulncheck.com, github.com
Which versions are affected by CVE-2026-122316?
kyverno: from 1.17.0 before 1.19.2.Source: cve.now feed data
Am I affected, and how do I check?
Kyverno versions 1.17.0 up to before 1.19.2 (the affected versions listed run up to v1.18.2) are in scope. The setup also requires a NamespacedMutatingPolicy with spec.evaluation.mutateExisting enabled and tenants permitted to create such policies. Check the installed Kyverno version and search the cluster for NamespacedMutatingPolicy resources that set mutateExisting.Source: vulncheck.com, github.com
How do I fix CVE-2026-122316?
Upgrade Kyverno to 1.19.2 or later, which contains the fix.Source: vulncheck.com, github.com