{"id":"CVE-2026-42955","url":"https://www.cyber-defence.io/tools/cve/CVE-2026-42955","generatedAt":"2026-10-28T09:26:28.412Z","title":"In NLnet Labs Unbound 1.16.2 up to and including 1.25.1, a similar vulnerability as with CVE-2026-40622 in the 'ghost domain names' family of attacks was found in Unbound that could extend the ghost domain window by up to one cached TTL configured value…","description":"In NLnet Labs Unbound 1.16.2 up to and including 1.25.1, a similar vulnerability as with CVE-2026-40622 in the 'ghost domain names' family of attacks was found in Unbound that could extend the ghost domain window by up to one cached TTL configured value for A/AAAA glue records. Similar to other 'ghost domain names' attacks, an adversary needs to control a (ghost) zone and be able to query a vulnerable Unbound. A single client A/AAAA query can cause Unbound to overwrite the cached expired parent-side glue rrset and essentially extend the ghost domain window by up to one cached TTL configured value ('cache-max-ttl'). In configurations where 'harden-referral-path: yes' is used (non-default configuration), no client query is required since Unbound implicitly performs that query. This is a variant of CVE-2026-40622 which only addressed the NS query.","published":"2026-07-22T14:17:19.000Z","lastModified":"2026-10-24T13:10:00.000Z","status":"Analyzed","sourceIdentifier":"sep@nlnetlabs.nl","cvss":{"version":"3.1","score":3.7,"severity":"LOW","vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:N"},"cwe":["CWE-672"],"affected":["nlnetlabs/unbound"],"epss":{"score":0.00196,"percentile":0.09173,"date":"2026-10-27","history":[]},"kev":{"listed":false},"exploits":{"count":0,"verified":false,"firstPublished":null,"source":"Exploit-DB (https://gitlab.com/exploit-database/exploitdb)","entries":[]},"verdict":{"level":"low","text":"Lower severity and a low EPSS score (0.20%). Track it; it rarely justifies an emergency change on its own."},"changes":[],"references":[{"url":"https://www.nlnetlabs.nl/downloads/unbound/CVE-2026-42955.txt","tags":["Vendor Advisory"],"source":"sep@nlnetlabs.nl"}],"sources":{"nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-42955","epss":"https://www.first.org/epss/","kev":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog","exploitdb":"https://www.exploit-db.com/"},"licence":"CC BY 4.0 — link back to the CVE Explorer if you publish the results; upstream data remains subject to its own terms."}