CVE-2023-34091 — kyverno
MEDIUMCVE-2023-34091 is a medium-severity (CVSS 6.5) CWE-285 vulnerability in github.com/kyverno/kyverno. A fix is available for github.com/kyverno/kyverno — see the affected versions and patch details below.
Kyverno resource with a deletionTimestamp may allow policy circumvention
Exploitation Status
No confirmed exploitation observed yet
- CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.
Exploitation and automatability from CISA’s SSVC triage for CVE-2023-34091.
EPSS Exploitation Probability
EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.
How urgent is this, really
CVE-2023-34091 plotted by exploitation likelihood (EPSS) against impact (CVSS). The shaded corner — EPSS 50%+ and CVSS 7.0+ — is where this CVE doesn't sit, though severity or exploitability alone can still warrant action.
Where this sits among everything scored
Of 377,636 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Real counts from FIRST.org, not a sample — log-scaled since the landscape is heavily right-skewed.
Real-World Exposure
github.com/kyverno/kyvernoReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects Go packages — download data is not available via public APIs for these ecosystems.
Description
Impact
In versions of Kyverno prior to 1.10.0, resources which have the deletionTimestamp field defined can bypass validate, generate, or mutate-existing policies, even in cases where the validationFailureAction field is set to Enforce.
This situation occurs as resources pending deletion were being consciously exempted by Kyverno, as a way to reduce processing load as policies are typically not applied to objects which are being deleted.
However, this could potentially result in allowing a malicious user to leverage the Kubernetes finalizers feature by setting a finalizer which causes the Kubernetes API server to set the deletionTimestamp and then not completing the delete operation as a way to explicitly to bypass a Kyverno policy.
Note that this is not applicable to Kubernetes Pods but, as an example, a Kubernetes Service resource can be manipulated using an indefinite finalizer to bypass policies.
Patches
This is resolved in Kyverno 1.10.0.
Workarounds
There is no known workaround.
References
Are there any links users can visit to find out more?
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐹Go | github.com/kyverno/kyverno | all versions | 1.10.0go get github.com/kyverno/kyverno@v1.10.0 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for github.com/kyverno/kyverno, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update github.com/kyverno/kyverno to 1.10.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2023-34091 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like CVE-2023-34091 can be triaged on real exposure rather than presence alone.
Tailored to CVE-2023-34091. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is CVE-2023-34091 in your dependencies?
O3 Security finds CVE-2023-34091 across Go dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.