{"id":"AZL-101721","summary":"CVE-2026-81634 affecting package unbound 1.26.0-1","details":"In NLnet Labs Unbound up to and including 1.26.0, a 255 length query name with a large TCP response can lead to a heap buffer overflow during the RRSet canonicalisation routine. This is caused by missing to add the first owner name into the buffer length check. A malicious actor operating a malicious name server or tampering with an incoming response to Unbound (canonicalisation happens before DNSSEC validation), can trigger the vulnerability.","modified":"2026-09-18T05:37:08Z","published":"2026-09-16T09:17:06Z","upstream":["CVE-2026-81634"],"references":[{"type":"WEB","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-81634"}],"affected":[{"package":{"name":"unbound","ecosystem":"Azure Linux:3","purl":"pkg:rpm/azure-linux/unbound"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"last_affected":"1.26.0-1"}]}],"database_specific":{"source":"https://github.com/microsoft/AzureLinuxVulnerabilityData/blob/main/osv/AZL-101721.json"}}],"schema_version":"1.9.0"}