Executive brief
BIND is a widely used software suite for managing the Domain Name System (DNS), which translates human-readable web addresses into IP addresses. A vulnerability has been identified where BIND may incorrectly validate security records from child zones. This could allow a remote attacker to forge responses that falsely claim a legitimate website or service does not exist, potentially disrupting access to digital services or redirecting traffic.
Technical details
A vulnerability exists in BIND 9's handling of DNSSEC NSEC3 records. The software may incorrectly accept NSEC3 records from a child zone as valid even when they are malformed or incorrect. An unauthenticated remote attacker can exploit this by providing forged NSEC3 records, allowing them to generate authenticated NXDOMAIN (non-existent domain) responses for sibling zones. This is classified as a cryptographic signature verification failure (CWE-347). The attack requires specific timing or network conditions (AC:H) but can impact the integrity of DNS data across security boundaries. Patches are available in versions 9.20.26, 9.21.24, and 9.20.26-S1.
Affected products
- ISC BIND 9 9.18.0 through 9.18.50, 9.20.0 through 9.20.24, 9.21.0 through 9.21.23, 9.11.3-S1 through 9.18.50-S1, 9.20.9-S1 through 9.20.24-S1
Timeline
- 2026-07-15: other: Early notification issued
- 2026-07-22: advisory: Public disclosure of CVE-2026-10723
- 2026-07-22: patched: Fixed versions released