{"id":"DEBIAN-CVE-2026-5947","details":"Undefined behavior may result due to a race condition leading to a use-after-free violation.  If BIND receives an incoming DNS message signed with SIG(0), it begins work to validate that signature.  If, during that validation, the \"recursive-clients\" limit is reached (as would occur during a query flood), and that same DNS message is discarded per the limit, there is a brief window of time while the SIG(0) validation may attempt to read the now-discarded DNS message. This issue affects BIND 9 versions 9.20.0 through 9.20.22, 9.21.0 through 9.21.21, and 9.20.9-S1 through 9.20.22-S1. BIND 9 versions 9.18.28 through 9.18.49 and 9.18.28-S1 through 9.18.49-S1 are NOT affected.","modified":"2026-09-14T17:03:21.752706073Z","published":"2026-05-20T13:16:40.303Z","upstream":["CVE-2026-5947"],"references":[{"type":"ADVISORY","url":"https://security-tracker.debian.org/tracker/CVE-2026-5947"}],"affected":[{"package":{"name":"bind9","ecosystem":"Debian:13","purl":"pkg:deb/debian/bind9?arch=source&distro=trixie"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1:9.20.23-1~deb13u1"}]}],"versions":["1:9.20.11-4","1:9.20.15-1","1:9.20.15-1~deb13u1","1:9.20.15-1~deb13u1~bpo12+1","1:9.20.15-2","1:9.20.18-1","1:9.20.18-1~deb13u1","1:9.20.18-1~deb13u1~bpo12+1","1:9.20.19-1","1:9.20.19-1~bpo12+1","1:9.20.20-1","1:9.20.20-1~bpo12+1","1:9.20.21-1","1:9.20.21-1~deb13u1","1:9.20.21-1~deb13u1~bpo12+1","1:9.20.22-1","1:9.20.23-1~deb13u1~bpo12+1"],"ecosystem_specific":{"urgency":"not yet assigned"},"database_specific":{"source":"https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-5947.json"}},{"package":{"name":"bind9","ecosystem":"Debian:14","purl":"pkg:deb/debian/bind9?arch=source&distro=forky"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1:9.20.23-1"}]}],"versions":["1:9.20.11-4","1:9.20.15-1","1:9.20.15-1~deb13u1","1:9.20.15-1~deb13u1~bpo12+1","1:9.20.15-2","1:9.20.18-1","1:9.20.18-1~deb13u1","1:9.20.18-1~deb13u1~bpo12+1","1:9.20.19-1","1:9.20.19-1~bpo12+1","1:9.20.20-1","1:9.20.20-1~bpo12+1","1:9.20.21-1","1:9.20.21-1~deb13u1","1:9.20.21-1~deb13u1~bpo12+1","1:9.20.22-1","1:9.20.23-1~deb13u1","1:9.20.23-1~deb13u1~bpo12+1"],"ecosystem_specific":{"urgency":"not yet assigned"},"database_specific":{"source":"https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-5947.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H"}]}