Vulnerability in Isc Bind 9
CVE-2026-75029
In a query response, an attacker may send `named` multiple copies of a record that should only exist once (such as an SOA record). If the RDATA is the same on all the copies, the record is appended to the in-memory RDATA set, which can cause increased memory usage of the negative cache and possibly lead to other memory attack vectors. This issue affects BIND 9 versions 9.11.0 through 9.18.50, 9.20.0 through 9.20.27, 9.21.0 through 9.21.25, 9.11.3-S1 through 9.18.50-S1, and 9.20.9-S1 through 9.20.27-S1.
CVSS v3 metric
CVSS v3 base score 5.3 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L.
Affected products
Weakness classification (CWE)
References
- security-officer@isc.org (vendor-advisory)
- security-officer@isc.org (patch)
- security-officer@isc.org (patch)
Frequently asked questions
- What is CVE-2026-75029?
- CVE-2026-75029 is a medium-severity vulnerability in Isc Bind 9, classified under Asymmetric Resource Consumption (Amplification). CVSS score: 5.3/10. Published 2026-09-16.
- How severe is CVE-2026-75029?
- Medium severity. CVSS v3 base score is 5.3 out of 10.