{
  "affected": [
    {
      "ranges": [
        {
          "database_specific": {
            "extracted_events": [
              {
                "introduced": "7.5.4"
              },
              {
                "fixed": "8.2606.0"
              }
            ],
            "source": [
              "AFFECTED_FIELD",
              "REFERENCES"
            ]
          },
          "events": [
            {
              "introduced": "9b104f782c0dd9440db27305cd87fd68414fce16"
            },
            {
              "fixed": "bcda60a3692efdf0c8e44102528f5a0ebe0dec6d"
            },
            {
              "fixed": "13d51f0c8da399a5778d52353d2b2f848fdd40e9"
            }
          ],
          "repo": "https://github.com/rsyslog/rsyslog",
          "type": "GIT"
        }
      ]
    }
  ],
  "aliases": [
    "GHSA-8qmr-c66f-g368"
  ],
  "database_specific": {
    "cna_assigner": "GitHub_M",
    "cwe_ids": [
      "CWE-121"
    ],
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/61xxx/CVE-2026-61548.json"
  },
  "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.",
  "id": "CVE-2026-61548",
  "modified": "2026-09-20T11:30:16.367749024Z",
  "published": "2026-09-18T16:54:28.925Z",
  "references": [
    {
      "type": "WEB",
      "url": "http://www.openwall.com/lists/oss-security/2026/07/20/1"
    },
    {
      "type": "WEB",
      "url": "https://github.com/rsyslog/rsyslog/releases/tag/v8.2606.0"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/61xxx/CVE-2026-61548.json"
    },
    {
      "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"
    },
    {
      "type": "FIX",
      "url": "https://github.com/rsyslog/rsyslog/commit/bcda60a3692efdf0c8e44102528f5a0ebe0dec6d"
    },
    {
      "type": "FIX",
      "url": "https://github.com/rsyslog/rsyslog/pull/6991"
    }
  ],
  "schema_version": "1.9.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H",
      "type": "CVSS_V3"
    }
  ],
  "summary": "Rsyslog: mmpstrucdata stack buffer overflow with oversized RFC5424 structured data"
}