CVE-2026-10822 in BIND 9
Summary
by MITRE • 07/22/2026
If BIND encounters a particular invalid data structure in a DNS record, it will accept the invalid data, and may subsequently abort and exit.
BIND will first need to store a DNS record for a key (KEY, DNSKEY, etc.). That key must specify a PRIVATEDNS algorithm (253), and in the algorithm identifier, improperly give a length longer than the actual identifier data. The invalid identifier will be stored. If BIND later needs to render that record to text, it will use the invalid length during processing, leading to a consistency check failing. This issue affects BIND 9 versions 9.18.0 through 9.18.50, 9.20.0 through 9.20.24, 9.21.0 through 9.21.23, 9.18.11-S1 through 9.18.50-S1, and 9.20.9-S1 through 9.20.24-S1.
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Analysis
by VulDB Data Team • 08/15/2026
This vulnerability represents a critical memory safety issue in the Berkeley Internet Name Domain (BIND) DNS server implementation that can lead to denial of service conditions through controlled application termination. The flaw exists within the handling of DNS record structures, specifically when processing keys with PRIVATEDNS algorithm identifiers that contain malformed length specifications. According to CWE-125, this vulnerability stems from an out-of-bounds read condition that occurs during the rendering process of stored DNS records.
The technical implementation involves a specific data structure validation failure where BIND accepts invalid data during the initial storage phase of DNS keys such as KEY or DNSKEY records. When a PRIVATEDNS algorithm (algorithm identifier 253) is encountered with an incorrect length field that exceeds the actual identifier data, the system stores this malformed structure without proper validation. This acceptance of invalid data represents a failure in input sanitization and validation mechanisms that should occur during record parsing and storage operations.
During subsequent processing when BIND attempts to render the problematic record to text format for display or further processing, the stored invalid length field is used in calculations that eventually lead to consistency checks failing. The memory access patterns during this rendering phase cause a segmentation fault or similar abort condition that results in the application terminating unexpectedly. This behavior aligns with ATT&CK technique T1499.004 which involves network denial of service attacks through application crashes and system resource exhaustion.
The impact of this vulnerability extends beyond simple service interruption as it affects multiple version ranges within BIND 9 releases, creating widespread exposure across different deployment scenarios. Systems running affected versions are susceptible to remote denial of service attacks where malicious actors could craft specially formatted DNS records to trigger the abort condition. The vulnerability's exploitation requires minimal privileges and can be executed through standard DNS protocol interactions, making it particularly dangerous in production environments where DNS servers handle high volumes of traffic.
Security mitigations for this vulnerability include immediate patching of affected BIND installations to versions that contain the fix for proper length validation during DNS record processing. Network administrators should also implement monitoring for unusual DNS server termination events and consider deploying intrusion detection systems that can identify malformed DNS record patterns. Additionally, implementing rate limiting and access controls on DNS server interfaces can help reduce the effectiveness of potential exploitation attempts while patches are deployed. Organizations should also verify their BIND configurations to ensure proper input validation is in place for all incoming DNS records and consider implementing automated vulnerability scanning tools that can detect the presence of affected versions in their infrastructure.