{"id":"CVE-2026-61548","summary":"Rsyslog: mmpstrucdata stack buffer overflow with oversized RFC5424 structured data","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.","aliases":["GHSA-8qmr-c66f-g368"],"modified":"2026-09-19T03:47:20.662275742Z","published":"2026-09-18T16:54:28.925Z","related":["SUSE-SU-2026:23122-1","SUSE-SU-2026:23145-1","SUSE-SU-2026:3442-1","SUSE-SU-2026:3478-1","SUSE-SU-2026:3498-1","SUSE-SU-2026:3518-1","openSUSE-SU-2026:11407-1","openSUSE-SU-2026:21535-1"],"database_specific":{"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/61xxx/CVE-2026-61548.json","cna_assigner":"GitHub_M","cwe_ids":["CWE-121"]},"references":[{"type":"WEB","url":"http://www.openwall.com/lists/oss-security/2026/07/20/1"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/61xxx/CVE-2026-61548.json"},{"type":"FIX","url":"https://github.com/rsyslog/rsyslog/commit/bcda60a3692efdf0c8e44102528f5a0ebe0dec6d"},{"type":"FIX","url":"https://github.com/rsyslog/rsyslog/pull/6991"},{"type":"WEB","url":"https://github.com/rsyslog/rsyslog/releases/tag/v8.2606.0"},{"type":"ADVISORY","url":"https://github.com/rsyslog/rsyslog/security/advisories/GHSA-8qmr-c66f-g368"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-61548"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://github.com/rsyslog/rsyslog","events":[{"introduced":"9b104f782c0dd9440db27305cd87fd68414fce16"},{"fixed":"13d51f0c8da399a5778d52353d2b2f848fdd40e9"}],"database_specific":{"extracted_events":[{"introduced":"7.5.4"},{"fixed":"8.2606.0"}],"source":"AFFECTED_FIELD"}}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-61548.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H"}]}