Input validation error in ISC BIND - CVE-2026-78301
Published: September 16, 2026
Vulnerability identifier: #VU150220
CSH Severity: Low
CVSS v4: 5.9 [CVSS:4.0/AV:N/AC:L/AT:P/PR:H/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-78301
CWE-ID: CWE-20
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote user to cause BIND to return attacker-supplied DNS data.
The vulnerability exists due to improper input validation in the named zone database when loading a malformed zone containing an NS or DNAME node above its origin. A remote privileged user can insert a malformed zone to cause BIND to return attacker-supplied DNS data.
On servers that also provide recursion, BIND can follow the locally sourced zone cut and cache attacker-supplied records for names outside the configured zone. On purely authoritative servers, queries may return out-of-zone referrals without the AA flag.
Affected software
ISC BIND
How to mitigate CVE-2026-78301
Install security update from vendor's website.
ISC BIND - addressed in versions 9.20.29, 9.20.29-s1, 9.21.26