# CVE-2026-50243

## Summary

- **CVE ID:** CVE-2026-50243
- **Severity:** MEDIUM
- **CVSS Score:** 6.3 (CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:L/SA:N)
- **CWE:** CWE-348
- **Published:** Jul 22, 2026
- **Last Modified:** Jul 24, 2026

## 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.

## Affected Products

- NLnet Labs — Unbound (1.6.2)

## References

- [CNA](https://www.nlnetlabs.nl/downloads/unbound/CVE-2026-50243.txt)

## Exploitation Prediction (EPSS)

- **EPSS Score:** 0.10%
- **EPSS Percentile:** 1.1

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_Exported from OnDuty AI Vulnerability Intelligence on 2026-09-10._