What’s Vulnerable › Vulnerabilities
CVE-2026-50248: BOGUS configured primary hostname accepted for XFR in auth/rpz zones
- Severity: medium (CVSS 6.5 v3.1)
- Exploited in the wild: not listed in CISA KEV
- EPSS: 0.1% probability of exploitation in the next 30 days
- Public exploit or detection template: none known
- Published: 2026-07-22 · updated 2026-10-24
- Weakness: CWE-345
Description
In NLnet Labs Unbound 1.7.0 up to and including 1.25.1, when an auth/rpz zone has a configured primary hostname that resolves to BOGUS A/AAAA, it is still considered as a possible XFR endpoint. A malicious actor that can spoof the hostname's A/AAAA record (no valid RRSIG required) becomes the zone's XFR primary and can replaces the entire zone/the resolver's entire response policy.
Affected products
- NLnet Labs Unbound: from 1.7.0 before 1.25.2 — fixed in 1.25.2
How to fix
Upgrade to a fixed version: NLnet Labs Unbound 1.25.2. Check the vendor advisory for mitigations.
References
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