This page tracks the Ubuntu fix status. The vulnerability itself is described on the main CVE page.
View CVE-2026-81563 →
UBUNTU-CVE-2026-81563
A BIND resolver encountering an SVCB/HTTPS AliasMode record referencing 14 or more SVCB/HTTPS ServiceMode records may fail to properly deallocate inte...
Original description
The description as published by the source.
A BIND resolver encountering an SVCB/HTTPS AliasMode record referencing 14 or more SVCB/HTTPS ServiceMode records may fail to properly deallocate internal resources. If this happens repeatedly, resource exhaustion will eventually prevent the resolver from performing new recursive lookups. This issue affects BIND 9 versions 9.18.0 through 9.18.50, 9.20.0 through 9.20.27, 9.21.0 through 9.21.25, 9.18.11-S1 through 9.18.50-S1, and 9.20.9-S1 through 9.20.27-S1.
Source: OSV.dev (Open Source Vulnerabilities) OSV
Affected packages
Ubuntu:18.04:LTS
isc-dhcp
[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}]
Ubuntu:Pro:20.04:LTS
bind9
[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1:9.18.30-0ubuntu0.20.04.2+esm3"}]}]
Ubuntu:20.04:LTS
bind9-libs
[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}]
Ubuntu:22.04:LTS
bind9
[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1:9.18.39-0ubuntu0.22.04.7"}]}]
Ubuntu:22.04:LTS
bind9-libs
[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}]
Ubuntu:24.04:LTS
bind9
[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1:9.18.39-0ubuntu0.24.04.8"}]}]
Ubuntu:24.04:LTS
isc-dhcp
[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}]
Ubuntu:26.10
bind9
[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}]
Ubuntu:26.04:LTS
bind9
[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1:9.20.24-1ubuntu0.4"}]}]
Ubuntu:26.04:LTS
isc-dhcp
[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}]
References
- advisory ubuntu.com
- report ubuntu.com
- report cve.org
- report kb.isc.org