CVE-2026-50045 'max-global-quota' reset by DNSSEC validation restarts
Attackers can bypass upstream traffic limits in Unbound by triggering DNSSEC validation restarts, potentially enabling amplification attacks.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-50045?
CVE-2026-50045 is a medium-severity vulnerability in Nlnetlabs Unbound, published on 22 Jul 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official 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.
Weakness: CWE-406
Which versions are affected by CVE-2026-50045?
It affects 1 product.
Products include Nlnetlabs Unbound.
How do I fix CVE-2026-50045?
Upgrade to a fixed version.
Is CVE-2026-50045 being exploited?
There is no known exploitation of CVE-2026-50045 in the wild and no public exploit code.
Other vulnerabilities in Nlnetlabs Unbound
- CVE-2026-81642 Heap buffer overflow and possible Remote Code Execution when digesting DNSKEY
- CVE-2026-33278 Possible arbitrary code execution during DNSSEC validation
- CVE-2026-42944 Heap overflow with multiple NSID, COOKIE, PADDING EDNS options
- CVE-2026-42959 Crash during DNSSEC validation of malicious content
- CVE-2026-82717 CNAME synthesis could lead to heap corruption
Sources
Also known as ALPINE-CVE-2026-50045, AZL-92925, DEBIAN-CVE-2026-50045, ECHO-8b08-0176-8175, GHSA-pjhw-m9f8-mwqg, UBUNTU-CVE-2026-50045.