Medium severity · published Jul 22, 2026
CVE-2026-50045
'max-global-quota' reset by DNSSEC validation restarts
5.3
CVSS
0.5%
EPSS
No
On KEV
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.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Confidentiality
None
Integrity
None
Availability
Low
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.5% · higher than 40% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
UN
Unbound · NLnet Labs
1.22.0 before 1.25.2 · source: vendor, NVD
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-50045
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-50045
Vendor Advisory
https://www.nlnetlabs.nl/downloads/unbound/CVE-2026-50045.txt
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