{"id":"UBUNTU-CVE-2026-61548","details":"Rsyslog is a rocket-fast system for log processing. From 7.5.4 until 8.2606.0, the optional mmpstrucdata plugin's parseSD_PARAM function in plugins/mmpstrucdata/mmpstrucdata.c stores RFC5424 parameter values in a fixed pVal[32 * 1024] stack buffer and calls parsePARAM_VALUE without supplying the destination size. A remote unauthenticated attacker whose crafted RFC5424 message reaches an action using mmpstrucdata can provide a structured-data parameter larger than that buffer when MaxMessageSize permits it, causing an attacker-controlled stack overwrite. Deployments that do not install and use the plugin, or whose effective message-size limit remains below the required threshold, are not affected by this issue. The demonstrated impact is a crash and interruption of log collection; code execution is not demonstrated. This issue is fixed in version 8.2606.0.","modified":"2026-09-24T02:00:34.890407525Z","published":"2026-07-20T00:00:00Z","related":["USN-8598-1"],"upstream":["CVE-2026-61548"],"references":[{"type":"REPORT","url":"https://ubuntu.com/security/CVE-2026-61548"},{"type":"REPORT","url":"https://www.cve.org/CVERecord?id=CVE-2026-61548"},{"type":"REPORT","url":"https://github.com/rsyslog/rsyslog/security/advisories/GHSA-8qmr-c66f-g368"},{"type":"ADVISORY","url":"https://ubuntu.com/security/notices/USN-8598-1"}],"affected":[{"package":{"name":"rsyslog","ecosystem":"Ubuntu:14.04:LTS","purl":"pkg:deb/ubuntu/rsyslog?arch=source&distro=trusty"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["5.8.11-2ubuntu4","7.4.4-1ubuntu1","7.4.4-1ubuntu2","7.4.4-1ubuntu2.1","7.4.4-1ubuntu2.3","7.4.4-1ubuntu2.5","7.4.4-1ubuntu2.6","7.4.4-1ubuntu2.7"],"ecosystem_specific":{"binaries":[{"binary_name":"rsyslog","binary_version":"7.4.4-1ubuntu2.7"},{"binary_version":"7.4.4-1ubuntu2.7","binary_name":"rsyslog-gnutls"},{"binary_name":"rsyslog-gssapi","binary_version":"7.4.4-1ubuntu2.7"},{"binary_version":"7.4.4-1ubuntu2.7","binary_name":"rsyslog-mysql"},{"binary_version":"7.4.4-1ubuntu2.7","binary_name":"rsyslog-pgsql"},{"binary_name":"rsyslog-relp","binary_version":"7.4.4-1ubuntu2.7"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-61548.json"}},{"package":{"name":"rsyslog","ecosystem":"Ubuntu:Pro:16.04:LTS","purl":"pkg:deb/ubuntu/rsyslog?arch=source&distro=esm-infra-legacy%2Fxenial"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["8.12.0-1ubuntu2","8.12.0-1ubuntu3","8.14.0-2ubuntu1","8.14.0-2ubuntu2","8.16.0-1ubuntu1","8.16.0-1ubuntu2","8.16.0-1ubuntu3","8.16.0-1ubuntu3.1","8.16.0-1ubuntu3.1+esm1","8.16.0-1ubuntu3.1+esm2","8.16.0-1ubuntu3.1+esm3"],"ecosystem_specific":{"binaries":[{"binary_version":"8.16.0-1ubuntu3.1+esm3","binary_name":"rsyslog"},{"binary_name":"rsyslog-elasticsearch","binary_version":"8.16.0-1ubuntu3.1+esm3"},{"binary_version":"8.16.0-1ubuntu3.1+esm3","binary_name":"rsyslog-gnutls"},{"binary_version":"8.16.0-1ubuntu3.1+esm3","binary_name":"rsyslog-gssapi"},{"binary_name":"rsyslog-mysql","binary_version":"8.16.0-1ubuntu3.1+esm3"},{"binary_version":"8.16.0-1ubuntu3.1+esm3","binary_name":"rsyslog-pgsql"},{"binary_name":"rsyslog-relp","binary_version":"8.16.0-1ubuntu3.1+esm3"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-61548.json"}},{"package":{"name":"rsyslog","ecosystem":"Ubuntu:Pro:18.04:LTS","purl":"pkg:deb/ubuntu/rsyslog?arch=source&distro=esm-infra%2Fbionic"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["8.16.0-1ubuntu9","8.16.0-1ubuntu10","8.32.0-1ubuntu3","8.32.0-1ubuntu4","8.32.0-1ubuntu4.2","8.32.0-1ubuntu4.2+esm1"],"ecosystem_specific":{"binaries":[{"binary_version":"8.32.0-1ubuntu4.2+esm1","binary_name":"rsyslog"},{"binary_version":"8.32.0-1ubuntu4.2+esm1","binary_name":"rsyslog-czmq"},{"binary_version":"8.32.0-1ubuntu4.2+esm1","binary_name":"rsyslog-elasticsearch"},{"binary_version":"8.32.0-1ubuntu4.2+esm1","binary_name":"rsyslog-gnutls"},{"binary_name":"rsyslog-gssapi","binary_version":"8.32.0-1ubuntu4.2+esm1"},{"binary_name":"rsyslog-hiredis","binary_version":"8.32.0-1ubuntu4.2+esm1"},{"binary_version":"8.32.0-1ubuntu4.2+esm1","binary_name":"rsyslog-kafka"},{"binary_name":"rsyslog-mongodb","binary_version":"8.32.0-1ubuntu4.2+esm1"},{"binary_version":"8.32.0-1ubuntu4.2+esm1","binary_name":"rsyslog-mysql"},{"binary_name":"rsyslog-pgsql","binary_version":"8.32.0-1ubuntu4.2+esm1"},{"binary_name":"rsyslog-relp","binary_version":"8.32.0-1ubuntu4.2+esm1"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-61548.json"}},{"package":{"name":"rsyslog","ecosystem":"Ubuntu:Pro:20.04:LTS","purl":"pkg:deb/ubuntu/rsyslog?arch=source&distro=esm-infra%2Ffocal"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["8.1901.0-1ubuntu4","8.2001.0-1ubuntu1","8.2001.0-1ubuntu1.1","8.2001.0-1ubuntu1.3","8.2001.0-1ubuntu1.3+esm1"],"ecosystem_specific":{"binaries":[{"binary_version":"8.2001.0-1ubuntu1.3+esm1","binary_name":"rsyslog"},{"binary_name":"rsyslog-czmq","binary_version":"8.2001.0-1ubuntu1.3+esm1"},{"binary_name":"rsyslog-elasticsearch","binary_version":"8.2001.0-1ubuntu1.3+esm1"},{"binary_version":"8.2001.0-1ubuntu1.3+esm1","binary_name":"rsyslog-gnutls"},{"binary_name":"rsyslog-gssapi","binary_version":"8.2001.0-1ubuntu1.3+esm1"},{"binary_name":"rsyslog-hiredis","binary_version":"8.2001.0-1ubuntu1.3+esm1"},{"binary_name":"rsyslog-kafka","binary_version":"8.2001.0-1ubuntu1.3+esm1"},{"binary_name":"rsyslog-mongodb","binary_version":"8.2001.0-1ubuntu1.3+esm1"},{"binary_version":"8.2001.0-1ubuntu1.3+esm1","binary_name":"rsyslog-mysql"},{"binary_name":"rsyslog-openssl","binary_version":"8.2001.0-1ubuntu1.3+esm1"},{"binary_name":"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