CVE-2026-76163: CWE-617 Reachable Assertion in ISC BIND 9
If BIND is loaded with a "`named.conf`" file that contains no global "`options`" block, an attacker can send a query of QTYPE TKEY which may cause an assertion failure and subsequent unexpected program exit. This issue affects BIND 9 versions 9.20.0 through 9.20.27, 9.21.0 through 9.21.25, and 9.20.9-S1 through 9.20.27-S1.
AI Analysis
Technical Summary
The vulnerability CVE-2026-76163 in ISC BIND 9 arises when the DNS server is configured with a named.conf file lacking a global options block. An attacker can exploit this by sending a DNS query of type TKEY, which causes an assertion failure in the software, leading to an unexpected termination of the BIND process. This denial-of-service condition affects BIND 9 versions 9.20.0 to 9.20.27, 9.21.0 to 9.21.25, and 9.20.9-S1 to 9.20.27-S1. The CVSS v3.1 score is 7.5, indicating high severity due to network attack vector, low complexity, no privileges required, no user interaction, and impact limited to availability.
Potential Impact
Successful exploitation results in an assertion failure causing the BIND 9 server to exit unexpectedly, leading to denial of service. There is no impact on confidentiality or integrity according to the CVSS vector. The attack can be performed remotely without authentication or user interaction.
Mitigation Recommendations
Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. Until a patch is available, administrators should ensure that their named.conf configuration includes a global options block to mitigate the risk of this assertion failure. Monitoring for unusual BIND process terminations may help detect exploitation attempts.
CVE-2026-76163: CWE-617 Reachable Assertion in ISC BIND 9
Description
If BIND is loaded with a "`named.conf`" file that contains no global "`options`" block, an attacker can send a query of QTYPE TKEY which may cause an assertion failure and subsequent unexpected program exit. This issue affects BIND 9 versions 9.20.0 through 9.20.27, 9.21.0 through 9.21.25, and 9.20.9-S1 through 9.20.27-S1.
CVSS v3.1
Score 7.5high
Affected software
ISC
BIND 9
pkg:github/isc/bind9Run on your own infrastructure? Check whether these packages are installed with threat-finder — our free open-source scanner.
Weaknesses
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
The vulnerability CVE-2026-76163 in ISC BIND 9 arises when the DNS server is configured with a named.conf file lacking a global options block. An attacker can exploit this by sending a DNS query of type TKEY, which causes an assertion failure in the software, leading to an unexpected termination of the BIND process. This denial-of-service condition affects BIND 9 versions 9.20.0 to 9.20.27, 9.21.0 to 9.21.25, and 9.20.9-S1 to 9.20.27-S1. The CVSS v3.1 score is 7.5, indicating high severity due to network attack vector, low complexity, no privileges required, no user interaction, and impact limited to availability.
Potential Impact
Successful exploitation results in an assertion failure causing the BIND 9 server to exit unexpectedly, leading to denial of service. There is no impact on confidentiality or integrity according to the CVSS vector. The attack can be performed remotely without authentication or user interaction.
Mitigation Recommendations
Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. Until a patch is available, administrators should ensure that their named.conf configuration includes a global options block to mitigate the risk of this assertion failure. Monitoring for unusual BIND process terminations may help detect exploitation attempts.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- isc
- Date Reserved
- 2026-08-19T08:52:01.762Z
- Cvss Version
- 3.1
- State
- PUBLISHED
Threat ID: 6aaaa87255bf5e2cf5bb988a
Added to database: 09/16/2026, 14:32:18 UTC
Last enriched: 09/16/2026, 14:46:45 UTC
Last updated: 09/17/2026, 04:35:06 UTC
Views: 9
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