CVE-2026-78301
MEDIUMDescription
A malformed zone may contain an NS or DNAME node above its origin, which `named` treats as a zone cut. If an attacker inserts a malformed zone into a BIND authoritative server (e.g., via zone transfer), queries for names inside the configured zone then lose authoritative status and return an out-of-zone delegation. On a server that also provides recursion BIND can follow this locally sourced cut and cache attacker-supplied data, affecting names outside the configured zone. This situation persists as long as the malformed zone remains in the zone database. 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.
How to fix
TridentStack Control can deploy fixes like this automatically across your Windows, macOS, and Linux fleet. See how it works
Remediation is compiled from vendor and distribution security advisories. Always confirm against the linked source for your exact version and platform.
CVSS v3 Vector
Exploitability
Impact
CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:C/C:N/I:H/A:N
Exploit Intelligence
Low risk: more likely to be exploited than 8% of all known CVEs.
References
Related Vulnerabilities
Other CWE-349 vulnerabilities, ordered by exploit likelihood. View all
| CVE | Severity | CVSS | EPSS | Exploited | Fix |
|---|---|---|---|---|---|
| CVE-2019-9535 | Critical | 9.8 | 2.5% | - | - |
| CVE-2026-32162 | High | 8.4 | 1.9% | - | Fix |
| CVE-2018-1131 | High | 8.8 | 1.3% | - | - |
| CVE-2021-21374 | High | 8.1 | 1.0% | - | Fix |
| CVE-2024-21094 | Low | 3.7 | 0.8% | - | Fix |
| CVE-2025-40778 | High | 8.6 | 0.7% | - | Fix |
Common questions
How do I fix CVE-2026-78301?
Upgrade bind9 on debian unstable to 1:9.20.29-1 or later.
Is CVE-2026-78301 being actively exploited?
Not that we know of. CVE-2026-78301 is not in the CISA Known Exploited Vulnerabilities catalog. Its EPSS score of 0.18% is the estimated probability that it will be exploited in the next 30 days. That is higher than 8% of all scored CVEs.
How severe is CVE-2026-78301?
CVE-2026-78301 has a CVSS v3 base score of 5.8, rated medium. CVSS rates the technical impact if the vulnerability is exploited, not how likely that is, so weigh it alongside the exploit-prediction score when you decide what to patch first.
What does CVE-2026-78301 affect?
Published advisories record a fix for bind9 (Debian). Only products with a sourced advisory are listed, so treat this as what we can cite rather than a complete inventory.
Embed a live status badge for CVE-2026-78301
Markdown
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This product uses NVD data but is not endorsed or certified by the NVD. EPSS scores courtesy of FIRST.org (https://www.first.org/epss). Source: CISA KEV Catalog. Data as of 2026-09-17.