CVE-2026-77692: CWE-476 NULL Pointer Dereference in ISC BIND 9
An attacker can cause `named` to abort by sending a crafted DNS-over-HTTPS request with a cryptographically invalid SIG(0) record, and then closing the transport connection prematurely. 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
This vulnerability (CWE-476 NULL Pointer Dereference) in ISC BIND 9 allows an unauthenticated attacker to cause a denial of service by crashing the named process. The attack vector involves sending a specially crafted DNS-over-HTTPS request with an invalid SIG(0) signature record and closing the connection prematurely, triggering a NULL pointer dereference and aborting the server process. The issue affects multiple BIND 9 versions as specified.
Potential Impact
The impact is a denial of service (DoS) condition resulting from the named server process aborting. There is no confidentiality or integrity impact reported. The CVSS v3.1 score is 7.5 (high), reflecting the network attack vector, low attack complexity, no privileges required, no user interaction, and an impact limited to availability.
Mitigation Recommendations
Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. No official fix or patch links are provided in the available data. Users should monitor ISC advisories for updates and consider mitigating exposure to DNS-over-HTTPS requests from untrusted sources until a fix is available.
CVE-2026-77692: CWE-476 NULL Pointer Dereference in ISC BIND 9
Description
An attacker can cause `named` to abort by sending a crafted DNS-over-HTTPS request with a cryptographically invalid SIG(0) record, and then closing the transport connection prematurely. 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
This vulnerability (CWE-476 NULL Pointer Dereference) in ISC BIND 9 allows an unauthenticated attacker to cause a denial of service by crashing the named process. The attack vector involves sending a specially crafted DNS-over-HTTPS request with an invalid SIG(0) signature record and closing the connection prematurely, triggering a NULL pointer dereference and aborting the server process. The issue affects multiple BIND 9 versions as specified.
Potential Impact
The impact is a denial of service (DoS) condition resulting from the named server process aborting. There is no confidentiality or integrity impact reported. The CVSS v3.1 score is 7.5 (high), reflecting the network attack vector, low attack complexity, no privileges required, no user interaction, and an impact limited to availability.
Mitigation Recommendations
Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. No official fix or patch links are provided in the available data. Users should monitor ISC advisories for updates and consider mitigating exposure to DNS-over-HTTPS requests from untrusted sources until a fix is available.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- isc
- Date Reserved
- 2026-08-21T07:46:15.243Z
- Cvss Version
- 3.1
- State
- PUBLISHED
Threat ID: 6aaaa16f55bf5e2cf5b35d45
Added to database: 09/16/2026, 14:02:23 UTC
Last enriched: 09/16/2026, 14:16:48 UTC
Last updated: 09/17/2026, 00:49:01 UTC
Views: 9
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