How severe is CVE-2026-50045?

CVE-2026-50045 has a CVSS 3.x base score of 5.3, rated medium severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability low.

Is CVE-2026-50045 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (20th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2026-50045?

CVE-2026-50045 affects Nlnetlabs Unbound. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2026-50045?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

When was CVE-2026-50045 published?

CVE-2026-50045 was published on 2026-07-22 and last updated on 2026-07-24.

CVE-2026-50045

CVE-2026-50045 is a medium-severity vulnerability in Nlnetlabs Unbound with a CVSS 3.x base score of 5.3. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-406.

Key facts

Severity: Medium (CVSS 3.x base score 5.3)
EPSS exploit prediction: 0% (20th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-406
Affected product: Nlnetlabs Unbound
Published: 2026-07-22
Last modified: 2026-07-24

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.

Frequently asked questions

What is CVE-2026-50045?: 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.
How severe is CVE-2026-50045?: CVE-2026-50045 has a CVSS 3.x base score of 5.3, rated medium severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability low.
Is CVE-2026-50045 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (20th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-50045?: CVE-2026-50045 affects Nlnetlabs Unbound. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2026-50045?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2026-50045 published?: CVE-2026-50045 was published on 2026-07-22 and last updated on 2026-07-24.

References

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

Affected products (1)

cpe:2.3:a:nlnetlabs:unbound:*:*:*:*:*:*:*:*

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Other CWE-406 vulnerabilities

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CVE-2021-38487 — High (CVSS 8.2): RTI Connext Professional versions 4.1 to 6.1.0, and Connext Micro versions 2.4 and later are vulnerable when an…
CVE-2023-49203 — High (CVSS 7.5): Technitium 11.5.3 allows remote attackers to cause a denial of service (bandwidth amplification) because the DNSBomb…
CVE-2023-28456 — High (CVSS 7.5): An issue was discovered in Technitium through 11.0.2. It enables attackers to launch amplification attacks (3 times…
CVE-2023-28455 — High (CVSS 7.5): An issue was discovered in Technitium through 11.0.2. The forwarding mode enables attackers to create a query loop…

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