virtualenv: Command injection via --prompt in activate.bat (batch activator)

{
  "id": "31a53082593202644b1b2b91b8bbd5fbd6fc7749b08c8e2c0bd715a1784acaa8",
  "url": "https://osv.dev/vulnerability/CVE-2026-102937",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "virtualenv: Command injection via --prompt in activate.bat (batch activator)",
    "summary": "virtualenv is a tool for creating isolated virtual python environments. Prior to 21.7.12, BatchActivator.quote() returns prompt text unchanged before activate.bat inserts it into a cmd.exe set \"VAR=value\" statement. An attacker who influences --prompt, VIRTUALENV_PROMPT, or the corresponding configuration value can include a double quote that closes the assignment and leaves following cmd.exe operators as executable syntax. When a user activates the generated Windows environment, the injected commands run with that user's privileges. This issue is fixed in version 21.7.12.",
    "evidence": "osv:CVE-2026-102937",
    "products": [],
    "severity": "high",
    "structured": {
      "id": "CVE-2026-102937",
      "aliases": [
        "BIT-virtualenv-2026-102937",
        "CVE-2026-102937",
        "GHSA-x78j-v8h9-3j2q",
        "PYSEC-2026-4014"
      ],
      "metrics": [
        {
          "type": "CVSS_V4",
          "score": "CVSS:4.0/AV:L/AC:L/AT:P/PR:N/UI:P/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://github.com/pypa/virtualenv",
              "type": "GIT",
              "events": [
                {
                  "introduced": "0"
                },
                {
                  "fixed": "9666b42afc8d6103e765d77958d7bae782f5406e"
                },
                {
                  "fixed": "d721ff140ce4afdc2a9b76751e4584e25d9fbea6"
                }
              ],
              "database_specific": {
                "extracted_events": [
                  {
                    "range": [
                      {
                        "introduced": "0"
                      },
                      {
                        "fixed": "21.7.12"
                      }
                    ],
                    "source": "AFFECTED_FIELD",
                    "strategy": "StringRangeExpression"
                  },
                  {
                    "range": [
                      {
                        "fixed": "d721ff140ce4afdc2a9b76751e4584e25d9fbea6"
                      }
                    ],
                    "source": "REFERENCES_COMMIT"
                  },
                  {
                    "range": [
                      {
                        "fixed": "9666b42afc8d6103e765d77958d7bae782f5406e"
                      }
                    ],
                    "source": "REFERENCES_TAG",
                    "original_tag": "21.7.12"
                  }
                ]
              }
            }
          ],
          "versions": [
            "21.7.11",
            "21.7.10",
            "21.7.9",
            "21.7.8",
            "21.7.7",
            "21.7.6",
            "21.7.5",
            "21.7.4",
            "21.7.3",
            "21.7.2",
            "21.7.1",
            "21.7.0",
            "21.6.1",
            "21.6.0",
            "21.5.2",
            "21.5.1",
            "21.5.0",
            "21.4.3",
            "21.4.2",
            "21.4.1",
            "21.4.0",
            "21.3.3",
            "21.3.2",
            "21.3.1",
            "21.3.0",
            "21.2.4",
            "21.2.3",
            "21.2.2",
            "21.2.1",
            "21.2.0",
            "21.1.0",
            "21.0.0",
            "20.39.1",
            "20.39.0",
            "20.38.0",
            "20.37.0",
            "20.27.3",
            "20.27.2",
            "20.24.3",
            "20.3.0",
            "20.0.32",
            "20.0.7",
            "20.0.0b2",
            "20.0.0b1"
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-102937.json"
          }
        }
      ],
      "modified": "2026-10-28T02:30:51.736344081Z",
      "provider": "osv",
      "references": [
        "https://github.com/pypa/virtualenv/releases/tag/21.7.12",
        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/102xxx/CVE-2026-102937.json",
        "https://github.com/pypa/virtualenv/security/advisories/GHSA-x78j-v8h9-3j2q",
        "https://nvd.nist.gov/vuln/detail/CVE-2026-102937",
        "https://github.com/pypa/virtualenv/commit/d721ff140ce4afdc2a9b76751e4584e25d9fbea6",
        "https://github.com/pypa/virtualenv/pull/3250"
      ],
      "provider_metadata": {
        "cwe_ids": [
          "CWE-78"
        ],
        "cna_assigner": "GitHub_M",
        "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/102xxx/CVE-2026-102937.json"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2026-102937",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 520274,
  "published_at": "2026-09-29T20:56:13.998+00:00"
}