CVE-2021-20088
Improperly Controlled Modification of Object Prototype Attributes ('Prototype Pollution') in mootools-more 1.6.0 allows a malicious user to inject properties into Object.prototype.
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (1.45%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
Description
Improperly Controlled Modification of Object Prototype Attributes ('Prototype Pollution') in mootools-more 1.6.0 allows a malicious user to inject properties into Object.prototype.
- CVSS 3.1
- 8.8 HIGHCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
- EPSS
- 1.45% probability · 73th percentile
- Public exploits
- None in Exploit-DB
- CISA KEV
- Not listed
- Weakness
- CWE-1321
- Affected
- mootools/mootools-more
- Source
- vulnreport@tenable.com
EPSS 1.4% since 26 October 2026; no change recorded yet. Points are recorded when the score first appears and whenever it moves by a percentage point or more.
References
- https://github.com/BlackFan/client-side-prototype-pollution/blob/master/pp/mootools-more.mdExploit, Third Party Advisory
- https://github.com/BlackFan/client-side-prototype-pollution/blob/master/pp/mootools-more.mdExploit, Third Party Advisory
Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.