{"id":"UBUNTU-CVE-2026-67231","details":"RabbitMQ is a messaging and streaming broker. Prior to versions 3.13.15, 4.0.20, 4.1.11, 4.2.6, and 4.3.0, The trust-store plugin installs a verify_fun that overrides {bad_cert, unknown_ca} / {bad_cert, selfsigned_peer} when the presented cert \"matches\" a whitelisted one. The match key is extract_issuer_id/1 → public_key:pkix_issuer_id/2 → {IssuerName, SerialNumber} , both fields are taken verbatim from the presented certificate body and contain no public-key, SKI, fingerprint or signature material. is_whitelisted/1 is a pure ets:member lookup; the stored full DER is used only for list/0 display and is never compared against the presented cert. cacerts is [], so the whitelisted cert is never used as a trust anchor for path validation either. TLS client-authentication bypass: an attacker who knows the issuer DN + serial of any whitelisted certificate can connect with a forged self-signed cert. Preconditions include rabbitmq_trust_store plugin enabled and used as the TLS verify_fun Attacker knows or can guess the {Issuer, Serial} of at least one whitelisted cert (non-secret; exposed via CLI/logs/any cert copy). This issue is fixed in versions 3.13.15, 4.0.20, 4.1.11, 4.2.6, and 4.3.0.","modified":"2026-10-22T10:30:14.794672858Z","published":"2026-09-23T21:17:00Z","related":["USN-8933-1"],"upstream":["CVE-2026-67231"],"references":[{"type":"REPORT","url":"https://ubuntu.com/security/CVE-2026-67231"},{"type":"REPORT","url":"https://www.cve.org/CVERecord?id=CVE-2026-67231"},{"type":"REPORT","url":"https://github.com/rabbitmq/rabbitmq-server/security/advisories/GHSA-cw8c-4m83-9c6w"},{"type":"REPORT","url":"https://github.com/rabbitmq/rabbitmq-server/releases/tag/v4.2.6"},{"type":"REPORT","url":"https://github.com/rabbitmq/rabbitmq-server/releases/tag/v4.3.0"},{"type":"ADVISORY","url":"https://ubuntu.com/security/notices/USN-8933-1"}],"affected":[{"package":{"name":"rabbitmq-server","ecosystem":"Ubuntu:Pro:16.04:LTS","purl":"pkg:deb/ubuntu/rabbitmq-server?arch=source&distro=esm-infra-legacy%2Fxenial"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"3.5.7-1ubuntu0.16.04.4+esm3"}]}],"versions":["3.5.4-1","3.5.4-3","3.5.4-3.1","3.5.7-1","3.5.7-1ubuntu0.16.04.1","3.5.7-1ubuntu0.16.04.2","3.5.7-1ubuntu0.16.04.4","3.5.7-1ubuntu0.16.04.4+esm1","3.5.7-1ubuntu0.16.04.4+esm2"],"ecosystem_specific":{"binaries":[{"binary_version":"3.5.7-1ubuntu0.16.04.4+esm3","binary_name":"rabbitmq-server"}],"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-2026-67231.json"}},{"package":{"name":"rabbitmq-server","ecosystem":"Ubuntu:Pro:18.04:LTS","purl":"pkg:deb/ubuntu/rabbitmq-server?arch=source&distro=esm-infra%2Fbionic"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"3.6.10-1ubuntu0.5+esm1"}]}],"versions":["3.6.10-1","3.6.10-1ubuntu0.1","3.6.10-1ubuntu0.3","3.6.10-1ubuntu0.4","3.6.10-1ubuntu0.5"],"ecosystem_specific":{"binaries":[{"binary_name":"rabbitmq-server","binary_version":"3.6.10-1ubuntu0.5+esm1"}],"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-2026-67231.json"}},{"package":{"name":"rabbitmq-server","ecosystem":"Ubuntu:Pro:20.04:LTS","purl":"pkg:deb/ubuntu/rabbitmq-server?arch=source&distro=esm-infra%2Ffocal"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"3.8.3-0ubuntu0.3+esm2"}]}],"versions":["3.7.8-4ubuntu2","3.7.18-1","3.8.2-0ubuntu1","3.8.2-0ubuntu1.1","3.8.2-0ubuntu1.2","3.8.2-0ubuntu1.3","3.8.2-0ubuntu1.4","3.8.2-0ubuntu1.5","3.8.3-0ubuntu0.1","3.8.3-0ubuntu0.2","3.8.3-0ubuntu0.3","3.8.3-0ubuntu0.3+esm1"],"ecosystem_specific":{"binaries":[{"binary_name":"rabbitmq-server","binary_version":"3.8.3-0ubuntu0.3+esm2"}],"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-2026-67231.json"}},{"package":{"name":"rabbitmq-server","ecosystem":"Ubuntu:22.04:LTS","purl":"pkg:deb/ubuntu/rabbitmq-server?arch=source&distro=jammy"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"3.9.27-0ubuntu0.6"}]}],"versions":["3.8.9-3ubuntu1","3.9.8-1","3.9.8-2","3.9.8-3","3.9.8-5","3.9.8-6","3.9.13-1","3.9.13-1ubuntu0.22.04.1","3.9.13-1ubuntu0.22.04.2","3.9.27-0ubuntu0.1","3.9.27-0ubuntu0.2","3.9.27-0ubuntu0.5"],"ecosystem_specific":{"binaries":[{"binary_name":"rabbitmq-server","binary_version":"3.9.27-0ubuntu0.6"}],"availability":"No subscription required"},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-67231.json"}},{"package":{"name":"rabbitmq-server","ecosystem":"Ubuntu:24.04:LTS","purl":"pkg:deb/ubuntu/rabbitmq-server?arch=source&distro=noble"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"3.12.1-1ubuntu1.7"}]}],"versions":["3.12.1-1","3.12.1-1ubuntu1","3.12.1-1ubuntu1.2","3.12.1-1ubuntu1.4","3.12.1-1ubuntu1.6"],"ecosystem_specific":{"binaries":[{"binary_version":"3.12.1-1ubuntu1.7","binary_name":"rabbitmq-server"}],"availability":"No subscription required"},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-67231.json"}},{"package":{"name":"rabbitmq-server","ecosystem":"Ubuntu:26.04:LTS","purl":"pkg:deb/ubuntu/rabbitmq-server?arch=source&distro=resolute"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"4.0.5-10ubuntu5.2"}]}],"versions":["4.0.5-8ubuntu2","4.0.5-10ubuntu1","4.0.5-10ubuntu2","4.0.5-10ubuntu3","4.0.5-10ubuntu4","4.0.5-10ubuntu5","4.0.5-10ubuntu5.1"],"ecosystem_specific":{"availability":"No subscription required","binaries":[{"binary_name":"rabbitmq-server","binary_version":"4.0.5-10ubuntu5.2"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-67231.json"}}],"schema_version":"1.9.2","severity":[{"type":"CVSS_V4","score":"CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N"},{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N"},{"type":"Ubuntu","score":"medium"}]}