Medium severity · published Sep 16, 2026
CVE-2026-19662
qpcache NOQNAME proof use-after-free crashes recursive resolver
5.9
CVSS
0.5%
EPSS
No
On KEV
Description
An attacker may be able to cause a `named` resolver to abort. The attack requires inducing the victim resolver to send multiple queries for a DNSSEC-signed zone hosted by an authoritative server under the control of the attacker. If the auth responds with a particular sequence of crafted answers, and those answers arrive in a particular order with particular timing, the `named` resolver will encounter a use-after-free bug, and abort.
This issue affects BIND 9 versions 9.11.0 through 9.18.50, 9.20.0 through 9.20.27, 9.11.3-S1 through 9.18.50-S1, and 9.20.9-S1 through 9.20.27-S1.
CVSS vector
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H
Attack vector
Network
Complexity
High
Privileges
None
User interaction
None
Confidentiality
None
Integrity
None
Availability
High
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.5% · higher than 40% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
B9
BIND 9 · ISC
9.11.0 through 9.18.50; 9.20.0 through 9.20.27; 9.11.3-S1 through 9.18.50-S1; 9.20.9-S1 through 9.20.27-S1 · source: vendor
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-19662
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-19662
downloads.isc.org
https://downloads.isc.org/isc/bind9/9.20.29
kb.isc.org
https://kb.isc.org/docs/cve-2026-19662
More from BIND 9
9.8
CVE-2026-3593
Heap use-after-free vulnerability in BIND 9 DNS-over-HTTPS implementation
8.6
CVE-2026-13321
DNSSEC Validation Bypass via Out-of-Zone NSEC Next Field
8.1
CVE-2026-94300
Concurrent GSS-TSIG messages corrupt memory
7.8
CVE-2017-3141
Windows service and uninstall paths are not quoted when BIND is installed
7.5
CVE-2026-97313
Specific RPZ configurations and query patterns may result in an unexpected exit