CVE-2026-113721 (GCVE-0-2026-113721)
Vulnerability from cvelistv5
Published
2026-10-20 19:46
Modified
2026-10-28 16:41
CWE
  • CWE-59 - Improper Link Resolution Before File Access ('Link Following')
Summary
virtualenv is a tool for creating isolated virtual python environments. Prior to 21.14.9, ViaTemplateActivator._generate() removes an existing output only when Path.exists() is true, allowing a dangling symlink to survive and redirect generated activation content, while PyEnvCfg.write() opens pyvenv.cfg without first replacing an existing symbolic or hard link. Another local account that prepares final entries inside the destination can therefore cause environment creation to create or overwrite files outside the requested tree with constrained virtualenv-generated content and the invoking user's permissions. The destination parent must remain controlled by the environment owner during creation; concurrent parent-directory replacement is a separate concern. This issue is fixed in version 21.14.9.
Impacted products
Vendor Product Version
pypa virtualenv Version: < 21.14.9
Create a notification for this product.
Show details on NVD website


{
  "containers": {
    "adp": [
      {
        "metrics": [
          {
            "other": {
              "content": {
                "id": "CVE-2026-113721",
                "options": [
                  {
                    "Exploitation": "none"
                  },
                  {
                    "Automatable": "no"
                  },
                  {
                    "Technical Impact": "partial"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-10-28T16:41:41.590636Z",
                "version": "2.0.3"
              },
              "type": "ssvc"
            }
          }
        ],
        "providerMetadata": {
          "dateUpdated": "2026-10-28T16:41:59.056Z",
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
        },
        "title": "CISA ADP Vulnrichment"
      }
    ],
    "cna": {
      "affected": [
        {
          "product": "virtualenv",
          "vendor": "pypa",
          "versions": [
            {
              "status": "affected",
              "version": "\u003c 21.14.9"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "virtualenv is a tool for creating isolated virtual python environments. Prior to 21.14.9, ViaTemplateActivator._generate() removes an existing output only when Path.exists() is true, allowing a dangling symlink to survive and redirect generated activation content, while PyEnvCfg.write() opens pyvenv.cfg without first replacing an existing symbolic or hard link. Another local account that prepares final entries inside the destination can therefore cause environment creation to create or overwrite files outside the requested tree with constrained virtualenv-generated content and the invoking user\u0027s permissions. The destination parent must remain controlled by the environment owner during creation; concurrent parent-directory replacement is a separate concern. This issue is fixed in version 21.14.9."
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "attackComplexity": "HIGH",
            "attackVector": "LOCAL",
            "availabilityImpact": "LOW",
            "baseScore": 4.5,
            "baseSeverity": "MEDIUM",
            "confidentialityImpact": "LOW",
            "integrityImpact": "LOW",
            "privilegesRequired": "LOW",
            "scope": "UNCHANGED",
            "userInteraction": "NONE",
            "vectorString": "CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:L/I:L/A:L",
            "version": "3.1"
          }
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-59",
              "description": "CWE-59: Improper Link Resolution Before File Access (\u0027Link Following\u0027)",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-10-20T19:46:28.770Z",
        "orgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
        "shortName": "GitHub_M"
      },
      "references": [
        {
          "name": "https://github.com/pypa/virtualenv/security/advisories/GHSA-558c-9hv2-4prj",
          "tags": [
            "x_refsource_CONFIRM"
          ],
          "url": "https://github.com/pypa/virtualenv/security/advisories/GHSA-558c-9hv2-4prj"
        },
        {
          "name": "https://github.com/pypa/virtualenv/pull/3431",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/pypa/virtualenv/pull/3431"
        },
        {
          "name": "https://github.com/pypa/virtualenv/commit/d25f28699eefb1fc34a251e5adf2b5de844c36cd",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/pypa/virtualenv/commit/d25f28699eefb1fc34a251e5adf2b5de844c36cd"
        },
        {
          "name": "https://github.com/pypa/virtualenv/releases/tag/21.14.9",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/pypa/virtualenv/releases/tag/21.14.9"
        }
      ],
      "source": {
        "advisory": "GHSA-558c-9hv2-4prj",
        "discovery": "UNKNOWN"
      },
      "title": "virtualenv: Generated files can follow existing destination links"
    }
  },
  "cveMetadata": {
    "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
    "assignerShortName": "GitHub_M",
    "cveId": "CVE-2026-113721",
    "datePublished": "2026-10-20T19:46:28.770Z",
    "dateReserved": "2026-10-20T16:03:14.863Z",
    "dateUpdated": "2026-10-28T16:41:59.056Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2",
  "vulnerability-lookup:meta": {
    "vulnrichment": {
      "containers": "{\"cna\": {\"title\": \"virtualenv: Generated files can follow existing destination links\", \"problemTypes\": [{\"descriptions\": [{\"cweId\": \"CWE-59\", \"lang\": \"en\", \"description\": \"CWE-59: Improper Link Resolution Before File Access (\u0027Link Following\u0027)\", \"type\": \"CWE\"}]}], \"metrics\": [{\"cvssV3_1\": {\"attackComplexity\": \"HIGH\", \"attackVector\": \"LOCAL\", \"availabilityImpact\": \"LOW\", \"baseScore\": 4.5, \"baseSeverity\": \"MEDIUM\", \"confidentialityImpact\": \"LOW\", \"integrityImpact\": \"LOW\", \"privilegesRequired\": \"LOW\", \"scope\": \"UNCHANGED\", \"userInteraction\": \"NONE\", \"vectorString\": \"CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:L/I:L/A:L\", \"version\": \"3.1\"}}], \"references\": [{\"name\": \"https://github.com/pypa/virtualenv/security/advisories/GHSA-558c-9hv2-4prj\", \"tags\": [\"x_refsource_CONFIRM\"], \"url\": \"https://github.com/pypa/virtualenv/security/advisories/GHSA-558c-9hv2-4prj\"}, {\"name\": \"https://github.com/pypa/virtualenv/pull/3431\", \"tags\": [\"x_refsource_MISC\"], \"url\": \"https://github.com/pypa/virtualenv/pull/3431\"}, {\"name\": \"https://github.com/pypa/virtualenv/commit/d25f28699eefb1fc34a251e5adf2b5de844c36cd\", \"tags\": [\"x_refsource_MISC\"], \"url\": \"https://github.com/pypa/virtualenv/commit/d25f28699eefb1fc34a251e5adf2b5de844c36cd\"}, {\"name\": \"https://github.com/pypa/virtualenv/releases/tag/21.14.9\", \"tags\": [\"x_refsource_MISC\"], \"url\": \"https://github.com/pypa/virtualenv/releases/tag/21.14.9\"}], \"affected\": [{\"vendor\": \"pypa\", \"product\": \"virtualenv\", \"versions\": [{\"version\": \"\u003c 21.14.9\", \"status\": \"affected\"}]}], \"providerMetadata\": {\"orgId\": \"a0819718-46f1-4df5-94e2-005712e83aaa\", \"shortName\": \"GitHub_M\", \"dateUpdated\": \"2026-10-20T19:46:28.770Z\"}, \"descriptions\": [{\"lang\": \"en\", \"value\": \"virtualenv is a tool for creating isolated virtual python environments. Prior to 21.14.9, ViaTemplateActivator._generate() removes an existing output only when Path.exists() is true, allowing a dangling symlink to survive and redirect generated activation content, while PyEnvCfg.write() opens pyvenv.cfg without first replacing an existing symbolic or hard link. Another local account that prepares final entries inside the destination can therefore cause environment creation to create or overwrite files outside the requested tree with constrained virtualenv-generated content and the invoking user\u0027s permissions. The destination parent must remain controlled by the environment owner during creation; concurrent parent-directory replacement is a separate concern. This issue is fixed in version 21.14.9.\"}], \"source\": {\"advisory\": \"GHSA-558c-9hv2-4prj\", \"discovery\": \"UNKNOWN\"}}, \"adp\": [{\"title\": \"CISA ADP Vulnrichment\", \"metrics\": [{\"other\": {\"type\": \"ssvc\", \"content\": {\"id\": \"CVE-2026-113721\", \"role\": \"CISA Coordinator\", \"options\": [{\"Exploitation\": \"none\"}, {\"Automatable\": \"no\"}, {\"Technical Impact\": \"partial\"}], \"version\": \"2.0.3\", \"timestamp\": \"2026-10-28T16:41:41.590636Z\"}}}], \"providerMetadata\": {\"orgId\": \"134c704f-9b21-4f2e-91b3-4a467353bcc0\", \"shortName\": \"CISA-ADP\", \"dateUpdated\": \"2026-10-28T16:41:53.012Z\"}}]}",
      "cveMetadata": "{\"cveId\": \"CVE-2026-113721\", \"assignerOrgId\": \"a0819718-46f1-4df5-94e2-005712e83aaa\", \"state\": \"PUBLISHED\", \"assignerShortName\": \"GitHub_M\", \"dateReserved\": \"2026-10-20T16:03:14.863Z\", \"datePublished\": \"2026-10-20T19:46:28.770Z\", \"dateUpdated\": \"2026-10-28T16:41:59.056Z\"}",
      "dataType": "CVE_RECORD",
      "dataVersion": "5.2"
    }
  }
}


Log in or create an account to share your comment.




Tags
Taxonomy of the tags.


Loading…

Loading…

Loading…

Sightings

Author Source Type Date

Nomenclature

  • Seen: The vulnerability was mentioned, discussed, or seen somewhere by the user.
  • Confirmed: The vulnerability is confirmed from an analyst perspective.
  • Published Proof of Concept: A public proof of concept is available for this vulnerability.
  • Exploited: This vulnerability was exploited and seen by the user reporting the sighting.
  • Patched: This vulnerability was successfully patched by the user reporting the sighting.
  • Not exploited: This vulnerability was not exploited or seen by the user reporting the sighting.
  • Not confirmed: The user expresses doubt about the veracity of the vulnerability.
  • Not patched: This vulnerability was not successfully patched by the user reporting the sighting.


Loading…

Loading…