{"id":"CVE-2018-16489","aliases":["EUVD-2019-0238","GHSA-675m-85rw-j3w4"],"status":"published","title":"Prototype Pollution in just-extend","description":"A prototype pollution vulnerability was found in just-extend \u003c4.0.0 that allows attack to inject properties onto Object.prototype through its functions.","severity":{"version":"3.1","score":9.8,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","level":"critical","assessor":"primary","from":"nvd"},"epss":{"day":"2026-11-09","score":0.01836,"percentile":0.79088,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":true},"cwes":["CWE-1321","CWE-400","CWE-74"],"published":"2019-02-01T18:00:00Z","modified":"2026-06-17T01:44:22Z","fixes":[{"ecosystem":"npm","package":"just-extend","fixed_in":["4.0.0"],"sources":["ghsa","osv"]}],"affected":[{"source":"ghsa","ecosystem":"npm","package":"just-extend","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"4.0.0"}]}]},{"source":"osv","ecosystem":"npm","package":"just-extend","ranges":[{"type":"SEMVER","events":[{"introduced":"0"},{"fixed":"4.0.0"}]}]}],"products":[{"vendor":"hackerone","product":"just-extend"},{"vendor":"just-extend_project","product":"just-extend"}],"references":[{"url":"https://hackerone.com/reports/430291","tags":["x_refsource_MISC","x_transferred","Exploit","Issue Tracking","Third Party Advisory","web"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2018-16489","tags":["advisory"]},{"url":"https://github.com/advisories/GHSA-675m-85rw-j3w4","tags":["advisory"]},{"url":"https://www.npmjs.com/advisories/780","tags":["web"]}],"sources":{"cve":[{"id":"CVE-2018-16489","description":"A prototype pollution vulnerability was found in just-extend \u003c4.0.0 that allows attack to inject properties onto Object.prototype through its functions.","status":"published","published":"2019-02-01T18:00:00Z","modified":"2024-08-05T10:24:32.562Z","cwes":["CWE-400"],"updated_at":"2026-11-02T14:35:11.072321Z"}],"euvd":[{"id":"EUVD-2019-0238","description":"A prototype pollution vulnerability was found in just-extend \u003c4.0.0 that allows attack to inject properties onto Object.prototype through its functions.","status":"published","published":"2019-02-01T18:00:00Z","modified":"2024-08-05T10:24:32Z","updated_at":"2026-11-03T02:39:41.299131Z"}],"ghsa":[{"id":"GHSA-675m-85rw-j3w4","title":"Prototype Pollution in just-extend","description":"Versions of `just-extend` before 4.0.0 are vulnerable to prototype pollution. Provided certain input `just-extend` can add or modify properties of the `Object` prototype. These properties will be present on all objects.\n\n\n## Recommendation\n\nUpdate to version `4.0.0` or later.","status":"published","published":"2019-02-07T18:17:12Z","modified":"2023-09-07T18:30:55Z","cvss":[{"version":"3.1","score":9.8,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","level":"critical"}],"cwes":["CWE-400","CWE-1321"],"updated_at":"2026-11-02T14:37:02.632342Z"}],"nvd":[{"id":"CVE-2018-16489","description":"A prototype pollution vulnerability was found in just-extend \u003c4.0.0 that allows attack to inject properties onto Object.prototype through its functions.","status":"published","published":"2019-02-01T18:29:00.987Z","modified":"2026-06-17T01:44:22.997Z","cvss":[{"version":"3.1","score":9.8,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","level":"critical","assessor":"primary"},{"version":"2.0","score":7.5,"vector":"AV:N/AC:L/Au:N/C:P/I:P/A:P","level":"high","assessor":"primary"}],"cwes":["CWE-400","CWE-74"],"updated_at":"2026-11-02T14:04:53.728218Z"}],"osv":[{"id":"GHSA-675m-85rw-j3w4","title":"Prototype Pollution in just-extend","description":"Versions of `just-extend` before 4.0.0 are vulnerable to prototype pollution. Provided certain input `just-extend` can add or modify properties of the `Object` prototype. These properties will be present on all objects.\n\n\n## Recommendation\n\nUpdate to version `4.0.0` or later.","status":"published","published":"2019-02-07T18:17:12Z","modified":"2023-11-08T04:00:00.870849Z","cvss":[{"version":"3.1","score":9.8,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","level":"critical"}],"cwes":["CWE-1321","CWE-400"],"updated_at":"2026-11-02T15:46:39.266402Z"}]}}