CVE-2026-96888: CWE-476 NULL Pointer Dereference in ISC BIND 9
Description
CVE-2026-96888 is a high severity vulnerability in ISC BIND 9 where a resolver configured with both a "redirect" zone and "qname-minimization strict" may abort due to an assertion failure caused by a NULL pointer dereference. This affects multiple BIND 9 versions from 9.16.0 through 9.21.26 and their respective S1 variants. The issue results in denial of service by crashing the resolver process.
CVSS v3.1
Score 7.5high
Affected software
ISC
BIND 9
pkg:deb/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 involves a NULL pointer dereference (CWE-476) in ISC BIND 9 resolvers configured with both a "redirect" zone and "qname-minimization strict" enabled. When processing the redirect, the resolver may hit an assertion failure and abort, causing a denial of service. The affected versions include 9.16.0 through 9.18.50, 9.20.0 through 9.20.29, 9.21.0 through 9.21.26, and their S1 variants. The CVSS 3.1 score is 7.5 (high severity) with network attack vector, low attack complexity, no privileges required, no user interaction, unchanged scope, no confidentiality or integrity impact, but high availability impact.
Potential Impact
Successful exploitation causes the BIND 9 resolver to abort unexpectedly, resulting in denial of service. There is no confidentiality or integrity impact reported. The resolver crash can disrupt DNS resolution services relying on the affected BIND 9 versions with the specified configuration.
Mitigation Recommendations
No explicit patch or remediation information is provided in the available data. Patch status is not yet confirmed — check the ISC vendor advisory for current remediation guidance. Until a fix is available, consider disabling either the "redirect" zone or "qname-minimization strict" feature to avoid triggering the assertion failure.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- isc
- Date Reserved
- 2026-09-23T18:38:48.888Z
- Cvss Version
- 3.1
- State
- PUBLISHED
Threat ID: 6ad8b86f2cdf04f656f0cad4
Added to database: 10/21/2026, 13:04:47 UTC
Last enriched: 10/21/2026, 13:15:46 UTC
Last updated: 10/21/2026, 13:40:20 UTC
Views: 8
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