A flaw was found in OpenDMARC. An encoding error in the Internationalized Domain Name (IDN) handler within the opendmarc_policy_query_dmarc function can cause domain name queries to fail or process incorrectly. A remote attacker could exploit this vulnerability by submitting specially crafted domain names, leading to improper email authentication policy evaluation or service disruption.
Last checked: 2026-10-01 15:34 UTC
Proof of concept · CISA Coordinator (Assessed 2026-10-01 13:55 UTC)
Fix evidence last checked: 2026-09-28 03:08 UTC