CVE-2026-50248

BOGUS configured primary hostname accepted for XFR in auth/rpz zones

MEDIUM
6.5
CVSS Score
Published: July 22, 2026 at 01:08 PM UTC
Updated: October 24, 2026 at 01:10 PM UTC
1 product affected across 1 vendorUnbound

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Severity
MEDIUM6.5
Exploit prediction
EPSS 0.1%
SSVC
No known exploit

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

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

1.7.0 ≤ v < 1.25.21.7.0
Affected range stops below 1.25.2, so it looks safe — our inference, not a vendor statement

Remediation

No guide yet

No remediation guidance has been written for this CVE yet. What the record does show:

References (1)

SSVC — Action Prioritization

SSVCNo known exploitNot automatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

6.5MEDIUMNLnet Labs
Vector?

Quick Info

StatusANALYZED
CWE
CWE-345

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