CVE-2026-50045

'max-global-quota' reset by DNSSEC validation restarts

Published Jul 22, 2026 CVSS 3.1 · 5.3 Medium EPSS < 1% KEV · Not listed
Description
In NLnet Labs Unbound 1.22.0 up to and including 1.25.1, a single client query for a deeply nested name under a DNSSEC-signed parent can cause Unbound to send more upstream packets per client query than the configured 'max-global-quota'. This effectively bypasses a security configuration that limits upstream amplification traffic.

Remediation

Vendor Solution

This issue is fixed starting with version 1.25.2

Tracking

Sign in to view the affected projects.

Advisories

Source ID Title
Debian DSA Debian DSA DSA-6507-1 unbound security update
History
Type Values Removed Values Added
First Time appeared Nlnetlabs
Nlnetlabs unbound
Vendors & Products Nlnetlabs
Nlnetlabs unbound
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'yes', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Type Values Removed Values Added
Description In NLnet Labs Unbound 1.22.0 up to and including 1.25.1, a single client query for a deeply nested name under a DNSSEC-signed parent can cause Unbound to send more upstream packets per client query than the configured 'max-global-quota'. This effectively bypasses a security configuration that limits upstream amplification traffic.
Title 'max-global-quota' reset by DNSSEC validation restarts
Weaknesses CWE-406
References
Metrics cvssV3_1

{'score': 5.3, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
NLnet Labs
Published
Updated
Jul 22, 2026, 6:57 PM
Reserved
Jun 22, 2026, 12:27 PM
Status
Analyzed
Published
Jul 22, 2026, 2:17 PM
Modified
Oct 24, 2026, 1:10 PM