CVE-2021-42581
CVSS v3
9.1
CRITICAL
EPSS Score
1.4 %
exploit probability, as of 2026-09-25
CISA KEV
No
known exploited
Exploitation
—
SSVC status
Description
Prototype poisoning in function mapObjIndexed in Ramda 0.27.0 and earlier allows attackers to compromise integrity or availability of application via supplying a crafted object (that contains an own property "__proto__") as an argument to the function. NOTE: the vendor disputes this because the observed behavior only means that a user can create objects that the user didn't know would contain custom prototypes
Technical details
- Published
- 2022-05-10
Frequently asked questions
What is CVE-2021-42581?
Prototype poisoning in function mapObjIndexed in Ramda 0.27.0 and earlier allows attackers to compromise integrity or availability of application via supplying a crafted object (that contains an own property "__proto__") as an argument to the function. NOTE: the vendor disputes this because the observed behavior only means that a user can create objects that the user didn't know would contain custom prototypes
Is CVE-2021-42581 actively exploited?
Active exploitation of CVE-2021-42581 has not been confirmed. Its EPSS score was 1.4% on 2026-09-25, the estimated probability of exploitation in the next 30 days.
What is the CVSS score for CVE-2021-42581?
CVE-2021-42581 has a CVSS v3 base score of 9.1 (CRITICAL severity).
Is CVE-2021-42581 affecting your environment?
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