CVE-2026-96888 PUBLISHED

Named may terminate unexpectedly when a redirect zone is used with strict QNAME minimization

Assigner: isc
Reserved: 23.09.2026 Published: 21.10.2026 Updated: 21.10.2026

A BIND resolver that is configured with both a "redirect" zone and "qname-minimization strict" may abort with an assertion failure while processing the redirect. This issue affects BIND 9 versions 9.16.0 through 9.18.50, 9.20.0 through 9.20.29, 9.21.0 through 9.21.26, 9.16.8-S1 through 9.18.50-S1, and 9.20.9-S1 through 9.20.29-S1.

Metrics

CVSS 3.1

CVSS Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
CVSS Score: 7.5

Attack Vector	Network	Scope	Unchanged
Attack Complexity	Low	Confidentiality Impact	None
Privileges Required	None	Integrity Impact	None
User Interaction	None	Availability Impact	High

CVSS 3.1

Product Status

Vendor	ISC
Product	BIND 9
Versions	Default: unaffected affected from 9.16.0 to 9.18.50 (incl.) affected from 9.20.0 to 9.20.29 (incl.) affected from 9.21.0 to 9.21.26 (incl.) affected from 9.16.8-S1 to 9.18.50-S1 (incl.) affected from 9.20.9-S1 to 9.20.29-S1 (incl.)

Exploits

We are not aware of any active exploits.

Workarounds

No workarounds known.

Solutions

Upgrade to the patched release most closely related to your current version of BIND 9: 9.20.30, 9.21.27, or 9.20.30-S1.

Credits

ISC would like to thank Vitaly Simonovich for bringing this vulnerability to our attention.