CVE Explorer
CVE-2026-42923
NLnet Labs Unbound up to and including version 1.25.0 has a vulnerability in the DNSSEC validator where the code path to consult the negative cache for DS records does not take into account the limit on NSEC3 hash calculations introduced in 1.19.1. This leads to degradation of service during the attack. An adversary that controls a DNSSEC signed zone can exploit this by signing NSEC3 records with acceptably high iterations for child delegations and querying a vulnerable Unbound. Unbound will kee
Known exploited
Not asserted
Disputed
No
Stale source
No
Conflicts
0
Affected products and versions
1 source assertion{"defaultStatus":"unaffected","product":"Unbound","vendor":"NLnet Labs","versions":[{"lessThan":"1.25.1","status":"affected","version":"0","versionType":"semver"}]}
- cve_program_cvelist_v5affectedurn:baitaphish:normalized-source-record:v2:282276812b6e9a07c2aab43ad159e04b0f9a55788fc5de4db9fc9039650c97aa · sha256:f8621b6d4449e109… · /containers/cna/affected/0
Provider-owned CVSS observations
1 source assertion{"metric":{"baseScore":6.9,"baseSeverity":"MEDIUM","vectorString":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/U:Amber","version":"4.0"},"metric_type":"cvssV4_0"}
- cve_program_cvelist_v5cvssurn:baitaphish:normalized-source-record:v2:282276812b6e9a07c2aab43ad159e04b0f9a55788fc5de4db9fc9039650c97aa · sha256:f8621b6d4449e109… · /containers/cna/metrics/0/cvssV4_0
CWE assertions
1 source assertion{"cweId":"CWE-407","description":"CWE-407: Inefficient Algorithmic Complexity","lang":"en","type":"CWE"}
- cve_program_cvelist_v5cweurn:baitaphish:normalized-source-record:v2:282276812b6e9a07c2aab43ad159e04b0f9a55788fc5de4db9fc9039650c97aa · sha256:f8621b6d4449e109… · /containers/cna/problemTypes/0/descriptions/0
Source references
1 source assertion{"tags":["vendor-advisory"],"url":"https://www.nlnetlabs.nl/downloads/unbound/CVE-2026-42923.txt"}
- cve_program_cvelist_v5referenceurn:baitaphish:normalized-source-record:v2:282276812b6e9a07c2aab43ad159e04b0f9a55788fc5de4db9fc9039650c97aa · sha256:f8621b6d4449e109… · /containers/cna/references/0
Attribution and limitations
- CVE Program CVEList V5: Reproduce the MITRE copyright designation and CVE license in copies. Source →
Provider severity values are preserved separately. Baitaphish does not convert them into a risk rating, infer affected products, or treat EPSS as observed exploitation.