{"id":"UBUNTU-CVE-2026-48551","details":"Nagios Core before 4.5.14 and Nagios XI before 2026R1.7 contain a cross-site request forgery protection bypass via a self-supplied double-submit cookie. An attacker can supply matching cookie and request parameter values to bypass CSRF protection, enabling unauthenticated attackers to run commands as authorized users via malicious links.","modified":"2026-08-19T11:05:27Z","published":"2026-08-12T17:17:00Z","upstream":["CVE-2026-48551"],"references":[{"type":"REPORT","url":"https://ubuntu.com/security/CVE-2026-48551"},{"type":"REPORT","url":"https://www.cve.org/CVERecord?id=CVE-2026-48551"},{"type":"REPORT","url":"https://github.com/NagiosEnterprises/nagioscore/blob/master/Changelog"},{"type":"REPORT","url":"https://www.nagios.com/security-disclosures/nagios-core/"},{"type":"REPORT","url":"https://www.vulncheck.com/advisories/nagios-core-xi-csrf-protection-bypass-via-double-submit-cookie"}],"affected":[{"package":{"name":"nagios4","ecosystem":"Ubuntu:20.04:LTS","purl":"pkg:deb/ubuntu/nagios4?arch=source&distro=focal"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["4.3.4-3","4.3.4-3ubuntu0.1"],"ecosystem_specific":{"binaries":[{"binary_name":"nagios4","binary_version":"4.3.4-3ubuntu0.1"},{"binary_name":"nagios4-cgi","binary_version":"4.3.4-3ubuntu0.1"},{"binary_name":"nagios4-common","binary_version":"4.3.4-3ubuntu0.1"},{"binary_version":"4.3.4-3ubuntu0.1","binary_name":"nagios4-core"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-48551.json"}},{"package":{"name":"nagios4","ecosystem":"Ubuntu:22.04:LTS","purl":"pkg:deb/ubuntu/nagios4?arch=source&distro=jammy"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["4.4.6-4","4.4.6-4ubuntu0.22.04.1"],"ecosystem_specific":{"binaries":[{"binary_version":"4.4.6-4ubuntu0.22.04.1","binary_name":"nagios4"},{"binary_name":"nagios4-cgi","binary_version":"4.4.6-4ubuntu0.22.04.1"},{"binary_name":"nagios4-common","binary_version":"4.4.6-4ubuntu0.22.04.1"},{"binary_version":"4.4.6-4ubuntu0.22.04.1","binary_name":"nagios4-core"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-48551.json"}},{"package":{"name":"nagios4","ecosystem":"Ubuntu:24.04:LTS","purl":"pkg:deb/ubuntu/nagios4?arch=source&distro=noble"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["4.4.6-4","4.4.6-4ubuntu0.24.04.1"],"ecosystem_specific":{"binaries":[{"binary_name":"nagios4","binary_version":"4.4.6-4ubuntu0.24.04.1"},{"binary_name":"nagios4-cgi","binary_version":"4.4.6-4ubuntu0.24.04.1"},{"binary_name":"nagios4-common","binary_version":"4.4.6-4ubuntu0.24.04.1"},{"binary_name":"nagios4-core","binary_version":"4.4.6-4ubuntu0.24.04.1"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-48551.json"}},{"package":{"name":"nagios4","ecosystem":"Ubuntu:26.04:LTS","purl":"pkg:deb/ubuntu/nagios4?arch=source&distro=resolute"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["4.4.6-4.1ubuntu1","4.4.6-4.1ubuntu2"],"ecosystem_specific":{"binaries":[{"binary_name":"nagios4","binary_version":"4.4.6-4.1ubuntu2"},{"binary_name":"nagios4-cgi","binary_version":"4.4.6-4.1ubuntu2"},{"binary_name":"nagios4-common","binary_version":"4.4.6-4.1ubuntu2"},{"binary_name":"nagios4-core","binary_version":"4.4.6-4.1ubuntu2"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-48551.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:N/I:H/A:N"},{"type":"CVSS_V4","score":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:N/VI:N/VA:N/SC:N/SI:H/SA:N"},{"type":"Ubuntu","score":"medium"}]}