CVE-2026-3104

High

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.

SeverityHigh

CVSS7.5

Exploit probability—

ProductIsc Bind

PublishedMar 25, 2026

First seenMar 25, 2026

Weakness typeCWE-772CWE-772

How to fix

Update

isc bind9.20.21, 9.21.20 or later

Patches

downloads.isc.org/isc/bind9/9.20.21
downloads.isc.org/isc/bind9/9.21.20

Vendor advisories

kb.isc.org/docs/cve-2026-3104
access.redhat.com/errata/RHSA-2026:6935

Affected products

Product	Affected versions	Fixed in
isc bind	9.20.0 ≤ v < 9.20.21, 9.21.0 ≤ v < 9.21.20	9.20.21, 9.21.20

Check your version

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