Kyverno 1.17.0 before 1.19.2 Cross-Namespace Privilege Escalation via NamespacedMutatingPolicy
Affects Kyverno 1.17.0 before 1.19.2 where a namespace-scoped tenant can create a NamespacedMutatingPolicy with mutateExisting, which runs under the cluster-wide background controller. 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 affected: <= 1.19.0 (per GHSA advisory); affected range 1.17.0 before 1.19.2 Attacker must be able to create a NamespacedMutatingPolicy with mutateExisting enabled and a targetMatchConstraints.expression Background controller ServiceAccount holds cluster-wide write permissions on the affected resources (no per-user impersonation)
- Last modified
- FIRST's estimate of the chance attackers exploit it in the next 30 days, updated daily.What do these mean? →
- 0.31% · 24th 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? →
- 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, in releases before the patched version contains a privilege escalation flaw in NamespacedMutatingPolicy that lets a namespace-scoped tenant modify resources in other namespaces. A remote attacker with low-privilege credentials can craft a target expression that points at another tenant's RoleBinding, causing the cluster-wide background controller to add attacker subjects or alter Roles, NetworkPolicies, and ConfigMaps.
Read the original description
Kyverno from 1.17.0 before 1.19.2 contains a privilege escalation vulnerability that allows namespace-scoped tenants to modify resources in other namespaces through NamespacedMutatingPolicy targetMatchConstraints.expression CEL output lacking namespace checks. Attackers can emit a literal target such as another tenant's RoleBinding, which the cluster-wide background controller then mutates to add attacker subjects or alter Roles, NetworkPolicies, and ConfigMaps.
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 affected: <= 1.19.0 (per GHSA advisory); affected range 1.17.0 before 1.19.2 Attacker must be able to create a NamespacedMutatingPolicy with mutateExisting enabled and a targetMatchConstraints.expression Background controller ServiceAccount holds cluster-wide write permissions on the affected resources (no per-user impersonation)Upgrade 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 1.17.0 · 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-2026-122313
Is CVE-2026-122313 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 namespace-scoped tenant can create a NamespacedMutatingPolicy that makes the cluster-wide background controller modify resources in other tenants' namespaces. The advisory gives examples such as adding subjects to a RoleBinding or changing Roles, NetworkPolicies, and ConfigMaps, which leads to cross-namespace privilege escalation.Source: github.com
Which versions are affected by CVE-2026-122313?
kyverno: from 1.17.0 before 1.19.2.Source: cve.now feed data
Am I affected, and how do I check?
The GHSA advisory lists Kyverno versions up to and including 1.19.0 as affected, within the range 1.17.0 before 1.19.2. The exposed setup requires NamespacedMutatingPolicy with mutateExisting enabled and a targetMatchConstraints.expression, and a background controller ServiceAccount with cluster-wide write permissions. Check the installed Kyverno version and whether NamespacedMutatingPolicy resources are in use.Source: github.com
How do I fix CVE-2026-122313?
Upgrade Kyverno to 1.19.2, which is the listed patched version. No workaround is listed in the facts.Source: github.com