DNSSEC Configuration Bypass in Unbound by NLnet Labs
CVE-2026-50045

5.3MEDIUM

Key Information:

Vendor

Nlnet Labs

Status
Unbound
Vendor
CVE Published:
22 July 2026

What is CVE-2026-50045?

In versions of Unbound ranging from 1.22.0 to 1.25.1, a flaw exists that permits an excessive number of upstream packets to be sent per client query. This occurs when a query targets a deeply nested name under a DNSSEC-signed parent domain, inadvertently bypassing the configured 'max-global-quota' security setting designed to limit amplification traffic. Consequently, this could result in unintentional Denial-of-Service scenarios, undermining the integrity of the DNS resolution process. It is essential for users of affected versions to review their configurations and apply necessary updates to mitigate this issue.

Affected Version(s)

Unbound 1.22.0 < 1.25.2

References

https://www.nlnetlabs.nl/downloads/unbound/CVE-2026-50045...
vendor-advisory

CVSS V3.1

Score:
5.3
Severity:
MEDIUM
Confidentiality:
None
Integrity:
None
Availability:
None
Attack Vector:
Network
Attack Complexity:
Low
Privileges Required:
None
User Interaction:
None
Scope:
Unchanged

Timeline

  • Vulnerability published

  • Vulnerability Reserved

Credit

Kunjie Shang (University of Science and Technology of China)
.