{"id":"CVE-2018-3722","aliases":["EUVD-2018-0254","GHSA-9g9w-hmvj-5h57"],"status":"published","title":"Prototype Pollution in merge-deep","description":"merge-deep node module before 3.0.1 suffers from a Modification of Assumed-Immutable Data (MAID) vulnerability, which allows a malicious user to modify the prototype of \"Object\" via __proto__, causing the addition or modification of an existing property that will exist on all objects.","severity":{"version":"3.0","score":8.8,"vector":"CVSS:3.0/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","level":"high","assessor":"primary","from":"nvd"},"epss":{"day":"2026-11-08","score":0.02004,"percentile":0.80937,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":true},"cwes":["CWE-471"],"published":"2018-06-07T02:00:00Z","modified":"2026-10-20T10:48:09Z","fixes":[{"ecosystem":"npm","package":"merge-deep","fixed_in":["3.0.1"],"sources":["ghsa","osv"]}],"affected":[{"source":"ghsa","ecosystem":"npm","package":"merge-deep","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"3.0.1"}]}]},{"source":"osv","ecosystem":"npm","package":"merge-deep","ranges":[{"type":"SEMVER","events":[{"introduced":"0"},{"fixed":"3.0.1"}]}]}],"products":[{"vendor":"hackerone","product":"merge-deep node module"},{"vendor":"merge-deep_project","product":"merge-deep"}],"references":[{"url":"https://github.com/jonschlinkert/merge-deep/commit/2c33634da7129a5aefcc262d2fec2e72224404e5","tags":["x_refsource_MISC","x_transferred","Patch","Third Party Advisory","fix","web"]},{"url":"https://hackerone.com/reports/310708","tags":["x_refsource_MISC","x_transferred","Exploit","Third Party Advisory","evidence","web"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2018-3722","tags":["advisory"]},{"url":"https://github.com/advisories/GHSA-9g9w-hmvj-5h57","tags":["advisory"]},{"url":"https://www.npmjs.com/advisories/580","tags":["web"]}],"sources":{"cve":[{"id":"CVE-2018-3722","description":"merge-deep node module before 3.0.1 suffers from a Modification of Assumed-Immutable Data (MAID) vulnerability, which allows a malicious user to modify the prototype of \"Object\" via __proto__, causing the addition or modification of an existing property that will exist on all objects.","status":"published","published":"2018-06-07T02:00:00Z","modified":"2024-09-17T04:14:35.263Z","cwes":["CWE-471"],"updated_at":"2026-11-02T14:35:05.262903Z"}],"euvd":[{"id":"EUVD-2018-0254","description":"merge-deep node module before 3.0.1 suffers from a Modification of Assumed-Immutable Data (MAID) vulnerability, which allows a malicious user to modify the prototype of \"Object\" via __proto__, causing the addition or modification of an existing property that will exist on all objects.","status":"published","published":"2018-06-07T02:00:00Z","modified":"2024-09-17T04:14:35Z","updated_at":"2026-11-03T00:28:24.821388Z"}],"ghsa":[{"id":"GHSA-9g9w-hmvj-5h57","title":"Prototype Pollution in merge-deep","description":"Versions of `merge-deep` before 3.0.1 are vulnerable to prototype pollution via merging functions.\n\n\n## Recommendation\n\nUpdate to version 3.0.1 or later.","status":"published","published":"2018-07-26T15:17:15Z","modified":"2023-09-07T18:19:35Z","cvss":[{"version":"3.0","score":8.8,"vector":"CVSS:3.0/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","level":"high"}],"cwes":["CWE-471"],"updated_at":"2026-11-02T14:37:02.632342Z"}],"nvd":[{"id":"CVE-2018-3722","description":"merge-deep node module before 3.0.1 suffers from a Modification of Assumed-Immutable Data (MAID) vulnerability, which allows a malicious user to modify the prototype of \"Object\" via __proto__, causing the addition or modification of an existing property that will exist on all objects.","status":"published","published":"2018-06-07T02:29:08.363Z","modified":"2026-06-17T01:57:43.463Z","cvss":[{"version":"3.0","score":8.8,"vector":"CVSS:3.0/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","level":"high","assessor":"primary"},{"version":"2.0","score":6.5,"vector":"AV:N/AC:L/Au:S/C:P/I:P/A:P","level":"medium","assessor":"primary"}],"cwes":["CWE-471"],"updated_at":"2026-11-02T14:04:28.483469Z"}],"osv":[{"id":"CVE-2018-3722","description":"merge-deep node module before 3.0.1 suffers from a Modification of Assumed-Immutable Data (MAID) vulnerability, which allows a malicious user to modify the prototype of \"Object\" via __proto__, causing the addition or modification of an existing property that will exist on all objects.","status":"published","published":"2018-06-07T02:29:08.363Z","modified":"2026-10-20T10:48:09.911709146Z","cvss":[{"version":"3.0","score":8.8,"vector":"CVSS:3.0/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","level":"high"}],"updated_at":"2026-11-02T15:44:09.442568Z"},{"id":"GHSA-9g9w-hmvj-5h57","title":"Prototype Pollution in merge-deep","description":"Versions of `merge-deep` before 3.0.1 are vulnerable to prototype pollution via merging functions.\n\n\n## Recommendation\n\nUpdate to version 3.0.1 or later.","status":"published","published":"2018-07-26T15:17:15Z","modified":"2023-11-08T04:00:17.242164Z","cvss":[{"version":"3.0","score":8.8,"vector":"CVSS:3.0/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","level":"high"}],"cwes":["CWE-471"],"updated_at":"2026-11-02T15:46:43.875515Z"}]}}