Description
A specially crafted domain can be used to cause a memory leak in a BIND resolver simply by querying this domain. This issue affects BIND 9 versions 9.20.0 through 9.20.20, 9.21.0 through 9.21.19, and 9.20.9-S1 through 9.20.20-S1. BIND 9 versions 9.18.0 through 9.18.46 and 9.18.11-S1 through 9.18.46-S1 are NOT affected.
Problem types
CWE-772 Missing Release of Resource after Effective Lifetime
Product status
9.20.0 (custom)
9.21.0 (custom)
9.20.9-S1 (custom)
9.18.0 (custom)
9.18.11-S1 (custom)
Credits
ISC would like to thank Vitaly Simonovich for bringing this vulnerability to our attention.
References
kb.isc.org/docs/cve-2026-3104 (CVE-2026-3104)
downloads.isc.org/isc/bind9/9.20.21
downloads.isc.org/isc/bind9/9.21.20