CVE-2026-19033

A flaw was found in bind. A remote attacker without a valid TSIG (Transaction Signature) can send unauthorized zone contents to a secondary server during a multi-message TCP IXFR (Incremental Zone Transfer). The named process may apply this unauthenticated data before the TSIG signature is verified. If the signature never arrives, named does not revert to its previous state, leading to the serving of unauthorized zone data and compromising information integrity.

Moderate: This vulnerability allows an attacker to provide unauthorized zone content to a secondary BIND server if it is configured for multi-message TCP IXFR transfers with TSIG restrictions. While TSIG is intended to secure zone transfers, the flaw prevents named from rolling back changes when a valid signature is not received, leading to potential data integrity issues.

The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.

Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base, or stability.