How severe is CVE-2021-23561?

CVE-2021-23561 has a CVSS 3.x base score of 6.5, rated medium severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity low, and availability low.

Is CVE-2021-23561 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (64th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-23561?

CVE-2021-23561 affects C2fo Comb. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2021-23561?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

When was CVE-2021-23561 published?

CVE-2021-23561 was published on 2021-12-10 and last updated on 2026-06-17.

CVE-2021-23561

CVE-2021-23561 is a medium-severity vulnerability in C2fo Comb with a CVSS 3.x base score of 6.5. 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: Medium (CVSS 3.x base score 6.5)
CVSS v2: 7.5
EPSS exploit prediction: 1% (64th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-1321
Affected product: C2fo Comb
Published: 2021-12-10
Last modified: 2026-06-17

Description

All versions of package comb are vulnerable to Prototype Pollution via the deepMerge() function.

Frequently asked questions

What is CVE-2021-23561?: All versions of package comb are vulnerable to Prototype Pollution via the deepMerge() function.
How severe is CVE-2021-23561?: CVE-2021-23561 has a CVSS 3.x base score of 6.5, rated medium severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity low, and availability low.
Is CVE-2021-23561 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (64th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-23561?: CVE-2021-23561 affects C2fo Comb. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2021-23561?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2021-23561 published?: CVE-2021-23561 was published on 2021-12-10 and last updated on 2026-06-17.

References

https://snyk.io/vuln/SNYK-JS-COMB-1730083

Affected products (1)

cpe:2.3:a:c2fo:comb:*:*:*:*:*:node.js:*:*

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