An out‑of‑bounds write can be triggered in PowerDNS DNSdist when an attacker sends specially crafted DNS responses that use the DNSQuestion:changeName or DNSResponse:changeName methods in custom Lua code. The rewritten packet may become larger than the original and exceed the 65535‑byte limit, causing the DNSdist process to crash. This crash results in a denial of service for clients relying on the affected DNS server. The weakness is classified as CWE‑787.

The vulnerability affects the DNSdist component of PowerDNS. No specific product or version numbers are disclosed in the advisory, so any deployment of DNSdist that processes or rewrites packets through the mentioned Lua methods is potentially at risk.

The CVSS score of 5.9 indicates moderate severity, while the EPSS score of less than 1% suggests a low likelihood of immediate exploitation. The vulnerability is not listed in the CISA KEV catalog. Based on the description, it is inferred that an attacker would need to send crafted DNS responses to a DNSdist instance that runs custom Lua scripts employing the changeName methods. Without such scripts, the attack surface is limited, but the potential for a crash remains a concern for environments requiring high availability.