{"id":"UBUNTU-CVE-2026-24401","details":"Avahi is a system which facilitates service discovery on a local network via the mDNS/DNS-SD protocol suite. In versions 0.9rc2 and below, avahi-daemon can be crashed via a segmentation fault by sending an unsolicited mDNS response containing a recursive CNAME record, where the alias and canonical name point to the same domain (e.g., \"h.local\" as a CNAME for \"h.local\"). This causes unbounded recursion in the lookup_handle_cname function, leading to stack exhaustion. The vulnerability affects record browsers where AVAHI_LOOKUP_USE_MULTICAST is set explicitly, which includes record browsers created by resolvers used by nss-mdns. This issue is patched in commit 78eab31128479f06e30beb8c1cbf99dd921e2524.","modified":"2026-05-22T17:19:32.285299766Z","published":"2026-01-24T02:15:00Z","related":["USN-8269-1"],"upstream":["CVE-2026-24401"],"references":[{"type":"REPORT","url":"https://ubuntu.com/security/CVE-2026-24401"},{"type":"REPORT","url":"https://www.cve.org/CVERecord?id=CVE-2026-24401"},{"type":"REPORT","url":"https://github.com/avahi/avahi/security/advisories/GHSA-h4vp-5m8j-f6w3"},{"type":"ADVISORY","url":"https://ubuntu.com/security/notices/USN-8269-1"}],"affected":[{"package":{"name":"avahi","ecosystem":"Ubuntu:Pro:14.04:LTS","purl":"pkg:deb/ubuntu/avahi?arch=source&distro=esm-infra-legacy%2Ftrusty"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"0.6.31-4ubuntu1.3+esm5"}]}],"versions":["0.6.31-2ubuntu4","0.6.31-2ubuntu5","0.6.31-3ubuntu1","0.6.31-4ubuntu1","0.6.31-4ubuntu1.1","0.6.31-4ubuntu1.2","0.6.31-4ubuntu1.3","0.6.31-4ubuntu1.3+esm1","0.6.31-4ubuntu1.3+esm2","0.6.31-4ubuntu1.3+esm3","0.6.31-4ubuntu1.3+esm4"],"ecosystem_specific":{"binaries":[{"binary_name":"avahi-autoipd","binary_version":"0.6.31-4ubuntu1.3+esm5"},{"binary_name":"avahi-daemon","binary_version":"0.6.31-4ubuntu1.3+esm5"},{"binary_version":"0.6.31-4ubuntu1.3+esm5","binary_name":"avahi-discover"},{"binary_name":"avahi-dnsconfd","binary_version":"0.6.31-4ubuntu1.3+esm5"},{"binary_name":"avahi-ui-utils","binary_version":"0.6.31-4ubuntu1.3+esm5"},{"binary_name":"avahi-utils","binary_version":"0.6.31-4ubuntu1.3+esm5"},{"binary_version":"0.6.31-4ubuntu1.3+esm5","binary_name":"libavahi-client3"},{"binary_version":"0.6.31-4ubuntu1.3+esm5","binary_name":"libavahi-common-data"},{"binary_name":"libavahi-common3","binary_version":"0.6.31-4ubuntu1.3+esm5"},{"binary_version":"0.6.31-4ubuntu1.3+esm5","binary_name":"libavahi-compat-libdnssd1"},{"binary_version":"0.6.31-4ubuntu1.3+esm5","binary_name":"libavahi-core7"},{"binary_version":"0.6.31-4ubuntu1.3+esm5","binary_name":"libavahi-glib1"},{"binary_version":"0.6.31-4ubuntu1.3+esm5","binary_name":"libavahi-gobject0"},{"binary_version":"0.6.31-4ubuntu1.3+esm5","binary_name":"libavahi-qt4-1"},{"binary_version":"0.6.31-4ubuntu1.3+esm5","binary_name":"libavahi-ui-gtk3-0"},{"binary_name":"libavahi-ui0","binary_version":"0.6.31-4ubuntu1.3+esm5"},{"binary_version":"0.6.31-4ubuntu1.3+esm5","binary_name":"python-avahi"}],"availability":"Available with Ubuntu Pro with Legacy support add-on: https://ubuntu.com/pro"},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-24401.json"}},{"package":{"name":"avahi","ecosystem":"Ubuntu:Pro:16.04:LTS","purl":"pkg:deb/ubuntu/avahi?arch=source&distro=esm-infra-legacy%2Fxenial"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"0.6.32~rc+dfsg-1ubuntu2.3+esm5"}]}],"versions":["0.6.31-4ubuntu4","0.6.32~rc+dfsg-1ubuntu2","0.6.32~rc+dfsg-1ubuntu2.1","0.6.32~rc+dfsg-1ubuntu2.2","0.6.32~rc+dfsg-1ubuntu2.3","0.6.32~rc+dfsg-1ubuntu2.3+esm1","0.6.32~rc+dfsg-1ubuntu2.3+esm2","0.6.32~rc+dfsg-1ubuntu2.3+esm3","0.6.32~rc+dfsg-1ubuntu2.3+esm4"],"ecosystem_specific":{"binaries":[{"binary_name":"avahi-autoipd","binary_version":"0.6.32~rc+dfsg-1ubuntu2.3+esm5"},{"binary_version":"0.6.32~rc+dfsg-1ubuntu2.3+esm5","binary_name":"avahi-daemon"},{"binary_version":"0.6.32~rc+dfsg-1ubuntu2.3+esm5","binary_name":"avahi-discover"},{"binary_version":"0.6.32~rc+dfsg-1ubuntu2.3+esm5","binary_name":"avahi-dnsconfd"},{"binary_version":"0.6.32~rc+dfsg-1ubuntu2.3+esm5","binary_name":"avahi-ui-utils"},{"binary_version":"0.6.32~rc+dfsg-1ubuntu2.3+esm5","binary_name":"avahi-utils"},{"binary_name":"libavahi-client3","binary_version":"0.6.32~rc+dfsg-1ubuntu2.3+esm5"},{"binary_name":"libavahi-common-data","binary_version":"0.6.32~rc+dfsg-1ubuntu2.3+esm5"},{"binary_version":"0.6.32~rc+dfsg-1ubuntu2.3+esm5","binary_name":"libavahi-common3"},{"binary_version":"0.6.32~rc+dfsg-1ubuntu2.3+esm5","binary_name":"libavahi-compat-libdnssd1"},{"binary_version":"0.6.32~rc+dfsg-1ubuntu2.3+esm5","binary_name":"libavahi-core7"},{"binary_version":"0.6.32~rc+dfsg-1ubuntu2.3+esm5","binary_name":"libavahi-glib1"},{"binary_version":"0.6.32~rc+dfsg-1ubuntu2.3+esm5","binary_name":"libavahi-gobject0"},{"binary_version":"0.6.32~rc+dfsg-1ubuntu2.3+esm5","binary_name":"libavahi-qt4-1"},{"binary_version":"0.6.32~rc+dfsg-1ubuntu2.3+esm5","binary_name":"libavahi-ui-gtk3-0"},{"binary_version":"0.6.32~rc+dfsg-1ubuntu2.3+esm5","binary_name":"libavahi-ui0"},{"binary_version":"0.6.32~rc+dfsg-1ubuntu2.3+esm5","binary_name":"python-avahi"}],"availability":"Available with Ubuntu Pro with Legacy support add-on: https://ubuntu.com/pro"},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-24401.json"}},{"package":{"name":"avahi","ecosystem":"Ubuntu:Pro:18.04:LTS","purl":"pkg:deb/ubuntu/avahi?arch=source&distro=esm-infra%2Fbionic"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"0.7-3.1ubuntu1.3+esm4"}]}],"versions":["0.6.32-1ubuntu1","0.7-3ubuntu1","0.7-3ubuntu2","0.7-3.1ubuntu1","0.7-3.1ubuntu1.1","0.7-3.1ubuntu1.2","0.7-3.1ubuntu1.3","0.7-3.1ubuntu1.3+esm1","0.7-3.1ubuntu1.3+esm2","0.7-3.1ubuntu1.3+esm3"],"ecosystem_specific":{"binaries":[{"binary_version":"0.7-3.1ubuntu1.3+esm4","binary_name":"avahi-autoipd"},{"binary_version":"0.7-3.1ubuntu1.3+esm4","binary_name":"avahi-daemon"},{"binary_version":"0.7-3.1ubuntu1.3+esm4","binary_name":"avahi-discover"},{"binary_version":"0.7-3.1ubuntu1.3+esm4","binary_name":"avahi-dnsconfd"},{"binary_name":"avahi-ui-utils","binary_version":"0.7-3.1ubuntu1.3+esm4"},{"binary_version":"0.7-3.1ubuntu1.3+esm4","binary_name":"avahi-utils"},{"binary_version":"0.7-3.1ubuntu1.3+esm4","binary_name":"gir1.2-avahi-0.6"},{"binary_version":"0.7-3.1ubuntu1.3+esm4","binary_name":"libavahi-client3"},{"binary_version":"0.7-3.1ubuntu1.3+esm4","binary_name":"libavahi-common-data"},{"binary_version":"0.7-3.1ubuntu1.3+esm4","binary_name":"libavahi-common3"},{"binary_version":"0.7-3.1ubuntu1.3+esm4","binary_name":"libavahi-compat-libdnssd1"},{"binary_version":"0.7-3.1ubuntu1.3+esm4","binary_name":"libavahi-core7"},{"binary_version":"0.7-3.1ubuntu1.3+esm4","binary_name":"libavahi-glib1"},{"binary_version":"0.7-3.1ubuntu1.3+esm4","binary_name":"libavahi-gobject0"},{"binary_version":"0.7-3.1ubuntu1.3+esm4","binary_name":"libavahi-ui-gtk3-0"},{"binary_version":"0.7-3.1ubuntu1.3+esm4","binary_name":"python-avahi"}],"availability":"Available with Ubuntu Pro (Infra-only): https://ubuntu.com/pro"},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-24401.json"}},{"package":{"name":"avahi","ecosystem":"Ubuntu:Pro:20.04:LTS","purl":"pkg:deb/ubuntu/avahi?arch=source&distro=esm-infra%2Ffocal"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"0.7-4ubuntu7.3+esm2"}]}],"versions":["0.7-4ubuntu5","0.7-4ubuntu6","0.7-4ubuntu7","0.7-4ubuntu7.1","0.7-4ubuntu7.2","0.7-4ubuntu7.3","0.7-4ubuntu7.3+esm1"],"ecosystem_specific":{"binaries":[{"binary_version":"0.7-4ubuntu7.3+esm2","binary_name":"avahi-autoipd"},{"binary_version":"0.7-4ubuntu7.3+esm2","binary_name":"avahi-daemon"},{"binary_version":"0.7-4ubuntu7.3+esm2","binary_name":"avahi-discover"},{"binary_version":"0.7-4ubuntu7.3+esm2","binary_name":"avahi-dnsconfd"},{"binary_name":"avahi-ui-utils","binary_version":"0.7-4ubuntu7.3+esm2"},{"binary_name":"avahi-utils","binary_version":"0.7-4ubuntu7.3+esm2"},{"binary_version":"0.7-4ubuntu7.3+esm2","binary_name":"gir1.2-avahi-0.6"},{"binary_version":"0.7-4ubuntu7.3+esm2","binary_name":"libavahi-client3"},{"binary_name":"libavahi-common-data","binary_version":"0.7-4ubuntu7.3+esm2"},{"binary_version":"0.7-4ubuntu7.3+esm2","binary_name":"libavahi-common3"},{"binary_name":"libavahi-compat-libdnssd1","binary_version":"0.7-4ubuntu7.3+esm2"},{"binary_version":"0.7-4ubuntu7.3+esm2","binary_name":"libavahi-core7"},{"binary_version":"0.7-4ubuntu7.3+esm2","binary_name":"libavahi-glib1"},{"binary_version":"0.7-4ubuntu7.3+esm2","binary_name":"libavahi-gobject0"},{"binary_version":"0.7-4ubuntu7.3+esm2","binary_name":"libavahi-ui-gtk3-0"},{"binary_version":"0.7-4ubuntu7.3+esm2","binary_name":"python-avahi"}],"availability":"Available with Ubuntu Pro (Infra-only): https://ubuntu.com/pro"},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-24401.json"}},{"package":{"name":"avahi","ecosystem":"Ubuntu:22.04:LTS","purl":"pkg:deb/ubuntu/avahi?arch=source&distro=jammy"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"0.8-5ubuntu5.5"}]}],"versions":["0.8-5ubuntu4","0.8-5ubuntu5","0.8-5ubuntu5.1","0.8-5ubuntu5.2","0.8-5ubuntu5.3","0.8-5ubuntu5.4"],"ecosystem_specific":{"binaries":[{"binary_version":"0.8-5ubuntu5.5","binary_name":"avahi-autoipd"},{"binary_name":"avahi-daemon","binary_version":"0.8-5ubuntu5.5"},{"binary_name":"avahi-discover","binary_version":"0.8-5ubuntu5.5"},{"binary_version":"0.8-5ubuntu5.5","binary_name":"avahi-dnsconfd"},{"binary_version":"0.8-5ubuntu5.5","binary_name":"avahi-ui-utils"},{"binary_version":"0.8-5ubuntu5.5","binary_name":"avahi-utils"},{"binary_version":"0.8-5ubuntu5.5","binary_name":"gir1.2-avahi-0.6"},{"binary_version":"0.8-5ubuntu5.5","binary_name":"libavahi-client3"},{"binary_name":"libavahi-common-data","binary_version":"0.8-5ubuntu5.5"},{"binary_version":"0.8-5ubuntu5.5","binary_name":"libavahi-common3"},{"binary_version":"0.8-5ubuntu5.5","binary_name":"libavahi-compat-libdnssd1"},{"binary_version":"0.8-5ubuntu5.5","binary_name":"libavahi-core7"},{"binary_version":"0.8-5ubuntu5.5","binary_name":"libavahi-glib1"},{"binary_version":"0.8-5ubuntu5.5","binary_name":"libavahi-gobject0"},{"binary_version":"0.8-5ubuntu5.5","binary_name":"libavahi-ui-gtk3-0"},{"binary_version":"0.8-5ubuntu5.5","binary_name":"python3-avahi"}],"availability":"No subscription required"},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-24401.json"}},{"package":{"name":"avahi","ecosystem":"Ubuntu:24.04:LTS","purl":"pkg:deb/ubuntu/avahi?arch=source&distro=noble"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"0.8-13ubuntu6.2"}]}],"versions":["0.8-10ubuntu1","0.8-13ubuntu1","0.8-13ubuntu2","0.8-13ubuntu4","0.8-13ubuntu5","0.8-13ubuntu6","0.8-13ubuntu6.1"],"ecosystem_specific":{"binaries":[{"binary_version":"0.8-13ubuntu6.2","binary_name":"avahi-autoipd"},{"binary_version":"0.8-13ubuntu6.2","binary_name":"avahi-daemon"},{"binary_version":"0.8-13ubuntu6.2","binary_name":"avahi-discover"},{"binary_name":"avahi-dnsconfd","binary_version":"0.8-13ubuntu6.2"},{"binary_name":"avahi-ui-utils","binary_version":"0.8-13ubuntu6.2"},{"binary_name":"avahi-utils","binary_version":"0.8-13ubuntu6.2"},{"binary_name":"gir1.2-avahi-0.6","binary_version":"0.8-13ubuntu6.2"},{"binary_version":"0.8-13ubuntu6.2","binary_name":"libavahi-client3"},{"binary_version":"0.8-13ubuntu6.2","binary_name":"libavahi-common-data"},{"binary_version":"0.8-13ubuntu6.2","binary_name":"libavahi-common3"},{"binary_version":"0.8-13ubuntu6.2","binary_name":"libavahi-compat-libdnssd1"},{"binary_version":"0.8-13ubuntu6.2","binary_name":"libavahi-core7"},{"binary_name":"libavahi-glib1","binary_version":"0.8-13ubuntu6.2"},{"binary_version":"0.8-13ubuntu6.2","binary_name":"libavahi-gobject0"},{"binary_version":"0.8-13ubuntu6.2","binary_name":"libavahi-ui-gtk3-0"},{"binary_version":"0.8-13ubuntu6.2","binary_name":"python3-avahi"}],"availability":"No subscription required"},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-24401.json"}},{"package":{"name":"avahi","ecosystem":"Ubuntu:25.10","purl":"pkg:deb/ubuntu/avahi?arch=source&distro=questing"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"0.8-16ubuntu3.2"}]}],"versions":["0.8-16ubuntu2","0.8-16ubuntu3","0.8-16ubuntu3.1"],"ecosystem_specific":{"binaries":[{"binary_version":"0.8-16ubuntu3.2","binary_name":"avahi-autoipd"},{"binary_name":"avahi-daemon","binary_version":"0.8-16ubuntu3.2"},{"binary_version":"0.8-16ubuntu3.2","binary_name":"avahi-discover"},{"binary_name":"avahi-dnsconfd","binary_version":"0.8-16ubuntu3.2"},{"binary_name":"avahi-ui-utils","binary_version":"0.8-16ubuntu3.2"},{"binary_version":"0.8-16ubuntu3.2","binary_name":"avahi-utils"},{"binary_version":"0.8-16ubuntu3.2","binary_name":"gir1.2-avahi-0.6"},{"binary_version":"0.8-16ubuntu3.2","binary_name":"libavahi-client3"},{"binary_version":"0.8-16ubuntu3.2","binary_name":"libavahi-common-data"},{"binary_version":"0.8-16ubuntu3.2","binary_name":"libavahi-common3"},{"binary_version":"0.8-16ubuntu3.2","binary_name":"libavahi-compat-libdnssd1"},{"binary_version":"0.8-16ubuntu3.2","binary_name":"libavahi-core7"},{"binary_version":"0.8-16ubuntu3.2","binary_name":"libavahi-glib1"},{"binary_version":"0.8-16ubuntu3.2","binary_name":"libavahi-gobject0"},{"binary_version":"0.8-16ubuntu3.2","binary_name":"libavahi-ui-gtk3-0"},{"binary_version":"0.8-16ubuntu3.2","binary_name":"python3-avahi"}],"availability":"No subscription required"},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-24401.json"}}],"schema_version":"1.7.5","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H"},{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H"},{"type":"Ubuntu","score":"medium"}]}