CVE-2026-71194
MediumCVSS 6.8Exploitation Probability (EPSS)
Low risk41th percentile - higher than 41% of all known CVEs
Summary
In OpenStack Designate before 22.0.2, the mDNS handler performs pool-blind lookups when resolving record queries and NOTIFY requests. When two zones with the same name exist across different pools, the lookup fails with a deterministic error, causing the handler to return REFUSED for all DNS queries through that path. The _handle_notify path is exploitable via a single unauthenticated UDP packet. This is independently reachable through the cross-tenant zone overlap described in a different recent CVE, and also affects legitimate same-tenant cross-pool configurations. BIND9 views do not mitigate this issue as mDNS is a shared service upstream of any view configuration.
Risk Assessment
An unauthenticated attacker can send a single UDP packet to cause DNS denial of service, potentially disrupting DNS-dependent services in the OpenStack environment.
Recommendation
Upgrade OpenStack Designate to version 22.0.2 or later that includes the fix. Restrict access to mDNS services from trusted networks.
Original NVD description (English source)
In OpenStack Designate before 22.0.2, the mDNS handler performs pool-blind lookups when resolving record queries and NOTIFY requests. When two zones with the same name exist across different pools, the lookup fails with a deterministic error, causing the handler to return REFUSED for all DNS queries through that path. The _handle_notify path is exploitable via a single unauthenticated UDP packet. This is independently reachable through the cross-tenant zone overlap described in a different recent CVE, and also affects legitimate same-tenant cross-pool configurations. BIND9 views do not mitigate this issue as mDNS is a shared service upstream of any view configuration.