CVE-2026-50243

Public on 2026-07-22
Modified on 2026-07-27
Description
In NLnet Labs Unbound 1.6.2 up to and including 1.25.1, when Unbound is configured with the 'respip' module in front of the validator together with a 'response-ip' redirect rule or an RPZ file with an RPZ-IP trigger, the rewriting handler does not check the security status of the upstream answer and can instead rewrite a BOGUS A/AAAA answer to point to an operator's configured IP. If the validator finds an expired or otherwise invalid RRSIG on an answer whose A record falls within a 'response-ip'/RPZ configuration, the answer is still rewritten and given a hard coded security level of INSECURE. This results in the client receiving an INSECURE NOERROR reply rewritten by the operator's configured IP. A malicious actor can exploit the possible poisonous effect by spoofing a BOGUS A/AAAA answer that falls inside the operator's configured subnet rewrites. Such DNSSEC protected answers are then insecurely redirected to the operator's configured target.
Severity
Low severity
Low
See what this means
CVSS v3 Base Score
3.7
See breakdown

Affected Packages

Platform Package Release Date Advisory Status
Amazon Linux 2 - Core unbound Pending Fix
Amazon Linux 2 - Unbound1.17 Extra unbound Pending Fix
Amazon Linux 2023 unbound Pending Fix

CVSS Scores

Score Type Score Vector
Amazon Linux CVSSv3 3.7 CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:N
NVD CVSSv3 3.7 CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:N