CVE-2026-10822 is a reachable assertion vulnerability in ISC BIND 9 DNS server software. When BIND encounters a DNS record with a PRIVATEDNS algorithm (253) that improperly specifies a length longer than the actual identifier data, it stores this invalid data. Later, if BIND attempts to render this record to text, it uses the invalid length during processing, causing a consistency check to fail and potentially leading to an abort and exit of the BIND process. This affects BIND 9 versions 9.18.0 through 9.18.50, 9.20.0 through 9.20.24, 9.21.0 through 9.21.23, and certain S1 variants. The vulnerability has a CVSS 3.1 base score of 6.5, indicating a medium severity with network attack vector, low attack complexity, no privileges required, user interaction required, unchanged scope, no confidentiality or integrity impact, but high availability impact.

Successful exploitation causes BIND to abort and exit, resulting in a denial of service condition. There is no impact on confidentiality or integrity, but availability of the DNS service is affected.

Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. Until a patch or official fix is available, administrators should monitor for updates from ISC and consider mitigating exposure to untrusted DNS data that could trigger this condition. No official fix or temporary workaround is currently documented.