Denial of Service Issue in BIND Server by ISC
CVE-2026-97313

7.5HIGH

Key Information:

Vendor

Isc
Status
Bind 9
Vendor
CVE Published:
21 October 2026

Badges

đź‘ľ Exploit Exists

What is CVE-2026-97313?

A recursive BIND server experiencing a query with recursion desired followed by a non-recursive query may suffer an assertion failure, leading to a denial of service. For this vulnerability to be exploitable, the server must permit recursive queries and be configured with two RPZ zones—one mandating recursive queries and the other not. Under these conditions, the server can crash, disrupting service availability.

Affected Version(s)

BIND 9 9.16.0 <= 9.18.50

BIND 9 9.20.0 <= 9.20.29

BIND 9 9.21.0 <= 9.21.26

References

https://kb.isc.org/docs/cve-2026-97313
vendor-advisory
https://downloads.isc.org/isc/bind9/9.20.30
patch
https://downloads.isc.org/isc/bind9/9.21.27
patch

CVSS V3.1

Score:
7.5
Severity:
HIGH
Confidentiality:
None
Integrity:
None
Availability:
None
Attack Vector:
Network
Attack Complexity:
Low
Privileges Required:
None
User Interaction:
None
Scope:
Unchanged

Timeline

  • đź‘ľ

    Exploit known to exist

  • Vulnerability published

  • Vulnerability Reserved

Credit

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