CVE-2026-3593

Weakness

A use-after-free vulnerability exists within the DNS-over-HTTPS implementation. This issue affects BIND 9 versions 9.20.0 through 9.20.22, 9.21.0 through 9.21.21, and 9.20.9-S1 through 9.20.22-S1. BIND 9 versions 9.18.0 through 9.18.48 and 9.18.11-S1 through 9.18.48-S1 are NOT affected.

Affected products

• isc bind

References

• https://downloads.isc.org/isc/bind9/9.20.23
• https://downloads.isc.org/isc/bind9/9.21.22
• https://kb.isc.org/docs/cve-2026-3593
• https://access.redhat.com/errata/RHSA-2026:7412
• https://access.redhat.com/security/cve/CVE-2026-3593
• https://bugzilla.redhat.com/show_bug.cgi?id=2479770