virtualenv activate runs commands from the environment name in zsh with PROMPT_SUBST

{
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2",
  "cveMetadata": {
    "cveId": "CVE-2026-113726",
    "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
    "assignerShortName": "GitHub_M",
    "dateUpdated": "2026-10-20T22:05:24.253Z",
    "dateReserved": "2026-10-20T16:03:14.863Z",
    "datePublished": "2026-10-20T22:05:24.253Z",
    "state": "PUBLISHED"
  },
  "containers": {
    "cna": {
      "providerMetadata": {
        "orgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
        "shortName": "GitHub_M",
        "dateUpdated": "2026-10-20T22:05:24.253Z"
      },
      "title": "virtualenv activate runs commands from the environment name in zsh with PROMPT_SUBST",
      "descriptions": [
        {
          "lang": "en",
          "value": "virtualenv is a tool for creating isolated virtual python environments. Prior to 21.13.0, the bash activate script that zsh also sources leaves the environment name unescaped; from 21.13.0 until 21.14.4, it escapes backslashes, dollar signs, and backticks only when BASH_VERSION is set, so zsh receives the raw value. The script assigns that value to PS1. In zsh with PROMPT_SUBST, an attacker-influenced environment directory, --prompt, or VIRTUALENV_PROMPT value containing command, parameter, or arithmetic expansion syntax can therefore execute commands in the user's shell each time the prompt is drawn. A percent sign is separately interpreted as a zsh prompt escape but does not by itself execute commands. Plain zsh with PROMPT_SUBST disabled and bash are not affected by this mechanism. This issue is fixed in version 21.14.4."
        }
      ],
      "affected": [
        {
          "vendor": "pypa",
          "product": "virtualenv",
          "versions": [
            {
              "version": "< 21.14.4",
              "status": "affected"
            }
          ]
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "lang": "en",
              "description": "CWE-78: Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection')",
              "cweId": "CWE-78",
              "type": "CWE"
            }
          ]
        },
        {
          "descriptions": [
            {
              "lang": "en",
              "description": "CWE-116: Improper Encoding or Escaping of Output",
              "cweId": "CWE-116",
              "type": "CWE"
            }
          ]
        }
      ],
      "references": [
        {
          "url": "https://github.com/pypa/virtualenv/security/advisories/GHSA-5vjq-rrrf-7h2q",
          "name": "https://github.com/pypa/virtualenv/security/advisories/GHSA-5vjq-rrrf-7h2q",
          "tags": [
            "x_refsource_CONFIRM"
          ]
        },
        {
          "url": "https://github.com/pypa/virtualenv/commit/5b915367da82bd024b2a0d28d2f98007034b4aa2",
          "name": "https://github.com/pypa/virtualenv/commit/5b915367da82bd024b2a0d28d2f98007034b4aa2",
          "tags": [
            "x_refsource_MISC"
          ]
        },
        {
          "url": "https://github.com/pypa/virtualenv/releases/tag/21.14.4",
          "name": "https://github.com/pypa/virtualenv/releases/tag/21.14.4",
          "tags": [
            "x_refsource_MISC"
          ]
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "version": "3.1",
            "vectorString": "CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H",
            "attackVector": "LOCAL",
            "attackComplexity": "LOW",
            "privilegesRequired": "NONE",
            "userInteraction": "REQUIRED",
            "scope": "UNCHANGED",
            "confidentialityImpact": "HIGH",
            "integrityImpact": "HIGH",
            "availabilityImpact": "HIGH",
            "baseScore": 7.8,
            "baseSeverity": "HIGH"
          }
        }
      ]
    }
  }
}