CVE-2026-27853: Powerdns Dnsdist

High severity, CVSS 7.5. EPSS: 1.5% chance of exploitation in the next 30 days.

An attacker might be able to trigger an out-of-bounds write by sending crafted DNS responses to a DNSdist using the DNSQuestion:changeName or DNSResponse:changeName methods in custom Lua code. In some cases the rewritten packet might become larger than the initial response and even exceed 65535 bytes, potentially leading to a crash resulting in denial of service.

Affected products

• Powerdns Dnsdist: from 1.9.0, before 1.9.12 (fixed in 1.9.12); from 2.0.0, before 2.0.3 (fixed in 2.0.3)

Published 2026-03-31. Last modified 2026-07-25.