CVE-2026-16543 Kong Operator cluster-wide ingress configuration DoS via embedded KIC CA-certificate ID collision
Namespace-scoped users can cause cluster-wide ingress denial of service by creating duplicate CA-certificate IDs in Secrets.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-16543?
CVE-2026-16543 is a high-severity denial of service vulnerability, published on 29 Jul 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Official description
Kong Operator's embedded Kong Kubernetes Ingress Controller (KIC) allows a user with namespace-scoped Secret creation privileges to cause a cluster-wide ingress configuration denial of service. The embedded KIC collects CA-certificate Secrets across all watched namespaces using a label selector alone, without ingress-class or namespace restrictions. The CA-certificate primary key is derived from a user-supplied field in the Secret. Duplicate CA-certificate IDs cause Kong Gateway to reject the entire configuration document and halting all ingress changes cluster-wide.
Which versions are affected by CVE-2026-16543?
How do I fix CVE-2026-16543?
No fix has been published for CVE-2026-16543 yet. Limit exposure of the affected software until one is available.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is CVE-2026-16543 being exploited?
There is no known exploitation of CVE-2026-16543 in the wild and no public exploit code.
Sources
Also known as GHSA-h4fh-j7xg-vwcx.