CVE-2021-42581

Name: CVE-2021-42581
Creator: NVD / NIST
Published: 2022-05-10T11:15:07.97+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

CRITICALCVSS 9.1/10EPSS 1.30%

Last modified Jun 17, 2026

CVE-2021-42581 is a critical-severity vulnerability rated 9.1/10 on the CVSS scale. 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. EPSS estimates a 1.30% chance of exploitation in the next 30 days.

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

Metrics

CVSS 3.1

9.1/10

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:H

EPSS Probability

1.30%

66.7th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-1321

Affected Software

Vendor	Product	Versions
Ramdajs	Ramda	<= 0.27.0

References

https://github.com/ramda/ramda/pull/3192Issue Tracking, Patch, Third Party Advisory
https://jsfiddle.net/3pomzw5g/2/Exploit, Third Party Advisory
https://github.com/ramda/ramda/pull/3192Issue Tracking, Patch, Third Party Advisory
https://jsfiddle.net/3pomzw5g/2/Exploit, Third Party Advisory

Timeline

Published: May 10, 2022
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2021-42581?

How severe is CVE-2021-42581?

CVE-2021-42581 has a CVSS score of 9.1/10 (CRITICAL severity). The EPSS model estimates a 1.30% probability of exploitation in the next 30 days.

How do I fix CVE-2021-42581?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2021-42581?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST