CVE-2026-50248
Description
A flaw in Unbound allows a remote attacker to replace an authenticated or Response Policy Zone (RPZ) by spoofing DNS records for configured primary hostnames. This enables the attacker to impersonate the primary server, leading to DNS cache poisoning or traffic redirection.
Statement
A Moderate impact flaw in Unbound allows a remote attacker to replace a resolver's Response Policy Zone (RPZ) by spoofing A/AAAA records for configured primary hostnames. If successful, an attacker can manipulate response policies, redirect traffic, or poison the DNS cache.
Mitigation
Configure Response Policy Zones (RPZ) and secondary zone primary endpoints using explicit IP addresses rather than hostnames to prevent A/AAAA spoofing or resolution flaws. Additionally, restrict network access for zone transfers to trusted sources and reload or restart the unbound service for configuration changes to take effect.
Common Vulnerability Scoring System (CVSS) Score Details
Info alert:Important note
CVSS scores for open source components depend on vendor-specific factors (e.g. version or build chain). Therefore, Red Hat's score and impact rating can be different from NVD and other vendors. Red Hat remains the authoritative CVE Naming Authority (CNA) source for its products and services (see Red Hat classifications).
CVSS v3 Score Breakdown
| Red Hat | NVD | cve.org | |
|---|---|---|---|
| Base Score | 6.5 | N/A | 6.5 |
| Attack Vector | Network | N/A | Network |
| Attack Complexity | High | N/A | High |
| Privileges Required | None | N/A | None |
| User Interaction | None | N/A | None |
| Scope | Unchanged | N/A | Unchanged |
| Confidentiality | None | N/A | None |
| Integrity Impact | High | N/A | High |
| Availability Impact | Low | N/A | Low |
Vector
Red Hat: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:L
cve.org: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:L
Understanding the Weakness (CWE)
Integrity,Other
Technical Impact: Varies by Context; Unexpected State
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