CVE-2026-50045: nlnet labs unbound
CVSS: 5.3v3.1MediumAnalyzed
AliasesALPINE-CVE-2026-50045UBUNTU-CVE-2026-50045DEBIAN-CVE-2026-50045
Published 22-07-2026Last modified 22-07-2026
Vulnerability summary
CVE-2026-50045 is a medium (CVSS 5.3) vulnerability in nlnet labs unbound. EPSS estimates a 0.46% chance of exploitation in the next 30 days, higher than 38.8% of scored vulnerabilities.
CVSS score
5.3/10
010
Medium · v3.1 (CVE.org)EPSS score
0.46%
0%100%
Low · +0.19 pp in 30 daysKEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits0No public exploits recorded
Advisory lineage
Upstream 0 · Downstream 10 · Related 7Timeline
- 22-07-2026PublishedVulnerability first disclosed.
- 22-07-2026Last modifiedVulnerability information updated.
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 metrics
5 scores · 5 sources · 1 versionMedium 5.3Preferred score · CVE.org (CNA)
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:LSourcesAll 5 agree
- OSV · AlpineEcosystem advisory · calculated5.3MediumCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
- OSV · UbuntuEcosystem advisory · calculated5.3MediumCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
- OSV · DebianEcosystem advisory · calculated5.3MediumCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
- NVDNIST5.3MediumCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
EPSS trend
Probability
0.46%
Chance of exploitation in the next 30 days
Percentile
39%
Versus all other CVEs
30-day change
+0.19 pp
From 0.28% on 19-09-2026
19-09-202619-10-2026
EPSS score0.46%
Known exploited
Compare KEV catalogsNot in any of the 3 tracked catalogs.
Public exploits
0 foundNo public exploits indexed.
Weaknesses
CWE · root causeAffected systems
Alpine1 product
- unbound≥ 1.22.0, < 1.25.2-r0
Debian1 product
- unboundAll versions (No fix recorded) | < 1.26.1-0+deb13u1 | < 1.25.2-1
Nlnet labs1 product
- unbound≥ 1.22.0, < 1.25.2
Nlnetlabs1 product
- unbound≥ 1.22.0, < 1.25.2
Ubuntu1 product
- unboundAll versions (No fix recorded)
5 vendors · 5 products
References
7 links- www.nlnetlabs.nl/downloads/unbound/CVE-2026-50045.txtVendor Advisory
