How severe is CVE-2021-25945?

CVE-2021-25945 has a CVSS 3.x base score of 9.8, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2021-25945 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 3% (86th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-25945?

CVE-2021-25945 affects Js-extend Project Js-extend. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2021-25945?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.

When was CVE-2021-25945 published?

CVE-2021-25945 was published on 2021-05-26 and last updated on 2026-06-17.

CVE-2021-25945

CVE-2021-25945 is a critical-severity vulnerability in Js-extend Project Js-extend with a CVSS 3.x base score of 9.8. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-1321.

Key facts

Severity: Critical (CVSS 3.x base score 9.8)
CVSS v2: 7.5
EPSS exploit prediction: 3% (86th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-1321
Affected product: Js-extend Project Js-extend
Published: 2021-05-26
Last modified: 2026-06-17

Description

Prototype pollution vulnerability in 'js-extend' versions 0.0.1 through 1.0.1 allows attacker to cause a denial of service and may lead to remote code execution.

Frequently asked questions

What is CVE-2021-25945?: Prototype pollution vulnerability in 'js-extend' versions 0.0.1 through 1.0.1 allows attacker to cause a denial of service and may lead to remote code execution.
How severe is CVE-2021-25945?: CVE-2021-25945 has a CVSS 3.x base score of 9.8, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2021-25945 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 3% (86th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-25945?: CVE-2021-25945 affects Js-extend Project Js-extend. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2021-25945?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.
When was CVE-2021-25945 published?: CVE-2021-25945 was published on 2021-05-26 and last updated on 2026-06-17.

References

https://www.whitesourcesoftware.com/vulnerability-database/CVE-2021-25945

Affected products (1)

cpe:2.3:a:js-extend_project:js-extend:*:*:*:*:*:node.js:*:*

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