CVE-2026-25518

Name of the Vulnerable Software and Affected Versions cert-manager versions 1.18.0 through 1.18.4 cert-manager versions 1.19.0 through 1.19.2

Description cert-manager simplifies the process of obtaining, renewing, and using certificates in Kubernetes clusters. The cert-manager-controller performs DNS lookups during ACME DNS-01 processing, which by default use unencrypted DNS. An attacker intercepting and modifying DNS traffic to the cert-manager-controller pod can insert a crafted entry into cert-manager’s DNS cache. Accessing this entry causes a panic, leading to a denial-of-service (DoS) condition of the cert-manager controller. Exploitation is also possible if a malicious actor controls the authoritative DNS server for the validated domain.

Recommendations Update to cert-manager version 1.18.5 or later. Update to cert-manager version 1.19.3 or later.