{"id":"CVE-2020-7616","aliases":["EUVD-2021-2587","GHSA-v39h-qm32-8gwq"],"status":"published","title":"Improperly Controlled Modification of Dynamically-Determined Object Attributes in express-mock-middleware","description":"express-mock-middleware through 0.0.6 is vulnerable to Prototype Pollution. Exported functions by the package can be tricked into adding or modifying properties of the `Object.prototype`. Exploitation of this vulnerability requires creation of a new directory where an attack code can be placed which will then be exported by `express-mock-middleware`. As such, this is considered to be a low risk.","severity":{"version":"3.1","score":5.3,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N","level":"medium","assessor":"primary","from":"nvd"},"epss":{"day":"2026-11-10","score":0.01274,"percentile":0.70138,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":false},"cwes":["CWE-1321","CWE-915"],"published":"2020-04-07T13:16:20Z","modified":"2026-06-17T03:25:07Z","affected":[{"source":"ghsa","ecosystem":"npm","package":"express-mock-middleware","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"last_affected":"0.0.6"}]}]},{"source":"osv","ecosystem":"npm","package":"express-mock-middleware","ranges":[{"type":"SEMVER","events":[{"introduced":"0"},{"last_affected":"0.0.6"}]}]}],"products":[{"vendor":"express-mock-middleware_project","product":"express-mock-middleware"}],"references":[{"url":"https://snyk.io/vuln/SNYK-JS-EXPRESSMOCKMIDDLEWARE-564120","tags":["x_refsource_MISC","x_transferred","Exploit","Third Party Advisory","web"]},{"url":"https://github.com/LingyuCoder/express-mock-middleware/blob/master/lib/index.js#L39","tags":["x_refsource_MISC","x_transferred","Third Party Advisory","web"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2020-7616","tags":["advisory"]},{"url":"https://github.com/advisories/GHSA-v39h-qm32-8gwq"}],"sources":{"cve":[{"id":"CVE-2020-7616","description":"express-mock-middleware through 0.0.6 is vulnerable to Prototype Pollution. Exported functions by the package can be tricked into adding or modifying properties of the `Object.prototype`. Exploitation of this vulnerability requires creation of a new directory where an attack code can be placed which will then be exported by `express-mock-middleware`. As such, this is considered to be a low risk.","status":"published","published":"2020-04-07T13:16:20Z","modified":"2024-08-04T09:33:19.989Z","updated_at":"2026-11-02T14:35:58.331892Z"}],"euvd":[{"id":"EUVD-2021-2587","description":"express-mock-middleware through 0.0.6 is vulnerable to Prototype Pollution. Exported functions by the package can be tricked into adding or modifying properties of the `Object.prototype`. Exploitation of this vulnerability requires creation of a new directory where an attack code can be placed which will then be exported by `express-mock-middleware`. As such, this is considered to be a low risk.","status":"published","published":"2020-04-07T13:16:20Z","modified":"2024-08-04T09:33:19Z","updated_at":"2026-11-03T03:07:59.058668Z"}],"ghsa":[{"id":"GHSA-v39h-qm32-8gwq","title":"Improperly Controlled Modification of Dynamically-Determined Object Attributes in express-mock-middleware","description":"express-mock-middleware through 0.0.6 is vulnerable to Prototype Pollution. Exported functions by the package can be tricked into adding or modifying properties of the `Object.prototype`. Exploitation of this vulnerability requires creation of a new directory where an attack code can be placed which will then be exported by `express-mock-middleware`. As such, this is considered to be a low risk.","status":"published","published":"2021-12-09T19:57:29Z","modified":"2023-01-27T05:08:06Z","cvss":[{"version":"3.1","score":5.3,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N","level":"medium"}],"cwes":["CWE-915","CWE-1321"],"updated_at":"2026-11-02T14:36:22.592333Z"}],"nvd":[{"id":"CVE-2020-7616","description":"express-mock-middleware through 0.0.6 is vulnerable to Prototype Pollution. Exported functions by the package can be tricked into adding or modifying properties of the `Object.prototype`. Exploitation of this vulnerability requires creation of a new directory where an attack code can be placed which will then be exported by `express-mock-middleware`. As such, this is considered to be a low risk.","status":"published","published":"2020-04-07T14:15:14.387Z","modified":"2026-06-17T03:25:07.523Z","cvss":[{"version":"3.1","score":5.3,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N","level":"medium","assessor":"primary"},{"version":"2.0","score":5,"vector":"AV:N/AC:L/Au:N/C:N/I:P/A:N","level":"medium","assessor":"primary"}],"cwes":["CWE-1321"],"updated_at":"2026-11-02T14:05:57.678762Z"}],"osv":[{"id":"GHSA-v39h-qm32-8gwq","title":"Improperly Controlled Modification of Dynamically-Determined Object Attributes in express-mock-middleware","description":"express-mock-middleware through 0.0.6 is vulnerable to Prototype Pollution. Exported functions by the package can be tricked into adding or modifying properties of the `Object.prototype`. Exploitation of this vulnerability requires creation of a new directory where an attack code can be placed which will then be exported by `express-mock-middleware`. As such, this is considered to be a low risk.","status":"published","published":"2021-12-09T19:57:29Z","modified":"2026-03-13T22:11:18.287185Z","cvss":[{"version":"3.1","score":5.3,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N","level":"medium"}],"cwes":["CWE-1321","CWE-915"],"updated_at":"2026-11-02T15:46:56.639206Z"}]}}