Activiti through 7.1.0.M6 Expression Injection via Mail Task

{
  "id": "cd2bc3c23638c434167e7a94db9c539d862ff797541ca4d01d58fe3b95910b1f",
  "url": "https://osv.dev/vulnerability/CVE-2026-91145",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "Activiti through 7.1.0.M6 Expression Injection via Mail Task",
    "summary": "Activiti through 7.1.0.M6 fails to validate hash-brace deferred expressions in process variables, allowing attackers to bypass expression filtering. Attackers can inject expressions beginning with #{ that are stored and later evaluated in the full Spring context when a mail task uses variable-backed body fields, enabling method invocation on application beans.",
    "evidence": "osv:CVE-2026-91145",
    "products": [],
    "severity": "high",
    "structured": {
      "id": "CVE-2026-91145",
      "aliases": [
        "CVE-2026-91145"
      ],
      "metrics": [
        {
          "type": "CVSS_V4",
          "score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:L/VA:N/SC:N/SI:N/SA:N"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://github.com/activiti/activiti",
              "type": "GIT",
              "events": [
                {
                  "introduced": "0"
                },
                {
                  "last_affected": "22d8f121451e049ea84a726064162b60d9b3aa69"
                }
              ],
              "database_specific": {
                "extracted_events": [
                  {
                    "range": [
                      {
                        "introduced": "0"
                      },
                      {
                        "last_affected": "7.1.0.M6"
                      }
                    ],
                    "source": "AFFECTED_FIELD",
                    "strategy": "StandardRange"
                  },
                  {
                    "range": [
                      {
                        "introduced": "0"
                      },
                      {
                        "last_affected": "7.1.0.M6"
                      }
                    ],
                    "source": "DESCRIPTION"
                  }
                ]
              }
            }
          ],
          "versions": [
            "7.1.0.M6",
            "activiti-7-201709-EA",
            "activiti-7-201708HOTFIX-EA",
            "activiti-7-201708-EA",
            "activiti-6.0.0",
            "activiti-6.0.0.RC1",
            "activiti-6.0.0.Beta4",
            "activiti-6.0.0.Beta3",
            "activiti-6.0.0.Beta2",
            "activiti-5.17.0",
            "activiti-5.16.4",
            "activiti-5.16.3",
            "activiti-5.16.2",
            "activiti-5.16.1",
            "activiti-5.16",
            "activiti-5.15",
            "activiti-5.14",
            "activiti-5.13",
            "activiti-5.12.1"
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-91145.json"
          }
        }
      ],
      "modified": "2026-10-28T02:30:38.591538888Z",
      "provider": "osv",
      "references": [
        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/91xxx/CVE-2026-91145.json",
        "https://nvd.nist.gov/vuln/detail/CVE-2026-91145",
        "https://www.vulncheck.com/advisories/activiti-through-7.1.0-m6-expression-injection-via-mail-task",
        "https://github.com/Activiti/Activiti/issues/5438",
        "https://github.com/Activiti/Activiti",
        "https://github.com/Activiti/Activiti/blob/7.1.0.M6/activiti-core/activiti-api-impl/activiti-api-process-runtime-impl/src/main/java/org/activiti/runtime/api/impl/ExpressionResolver.java",
        "https://github.com/Activiti/Activiti/blob/7.1.0.M6/activiti-core/activiti-engine/src/main/java/org/activiti/engine/impl/bpmn/behavior/MailActivityBehavior.java"
      ],
      "provider_metadata": {
        "cwe_ids": [
          "CWE-917"
        ],
        "cna_assigner": "VulnCheck",
        "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/91xxx/CVE-2026-91145.json"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2026-91145",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 506217,
  "published_at": "2026-09-14T21:45:45.317+00:00"
}