PatchTheCVECVE-2026-122303: Kyverno from 1.17.0 before 1.19.2 contains an authorization bypass vulnerability that allows namespace tenants
CVE-2026-122303 is a critical-severity flaw (CVSS 9.9) affecting affected software. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.
Kyverno from 1.17.0 before 1.19.2 contains an authorization bypass vulnerability that allows namespace tenants to overwrite resources in other namespaces via NamespacedMutatingPolicy mutate-existing targetMatchConstraints.expression. Attackers can return a CEL map literal fabricating a target with an attacker-chosen metadata.namespace, causing the privileged background controller to overwrite Secrets, Deployments, or policies cluster-wide.
Why this priority
- Critical severity
No fix is published yet: follow the downgrade or mitigation steps.
Risk facts
| CVSS score | 9.9 (Critical) |
| Attack vector | Network (remote) |
| Attack complexity | Low |
| Privileges needed | Low |
| User interaction | None |
| EPSS exploit chance | n/a |
| CISA exploited list | No |
| Weakness | CWE-862 |
| Published | 2026-11-05 |
| Last modified | 2026-11-05 |
Last updated 2026-11-05 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score
Timeline
- Published CVE record published
- Updated Record last modified
Advisories and coverage
Research and news
- VulDB Recent Entries: CVE-2026-122303 | Kyverno up to 1.19.1 NamespacedMutatingPolicy authorization 2026-11-05
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.
Quick answers
How do I fix CVE-2026-122303?
No fixed release is listed yet. Watch the vendor advisory and apply any mitigation shown on this page.
Is CVE-2026-122303 being exploited?
CVE-2026-122303 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.
What does CVE-2026-122303 affect?
CVE-2026-122303 affects affected software. Severity is critical (CVSS 9.9). Kyverno from 1.17.0 before 1.19.2 contains an authorization bypass vulnerability that allows namespace tenants to overwrite resources in other namespaces via NamespacedMutatingPolicy mutate-existing targetMatchConstraints.expression. Attack
How urgent is CVE-2026-122303?
Priority 35/100. Critical severity