How severe is CVE-2021-23426?

CVE-2021-23426 has a CVSS 3.x base score of 5.6, rated medium severity. It is exploitable over network with high attack complexity, requires no privileges and no user interaction. Impact on confidentiality is low, integrity low, and availability low.

Is CVE-2021-23426 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (54th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-23426?

CVE-2021-23426 affects Proto Project Proto. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2021-23426?

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

When was CVE-2021-23426 published?

CVE-2021-23426 was published on 2021-09-01 and last updated on 2026-06-17.

CVE-2021-23426

CVE-2021-23426 is a medium-severity vulnerability in Proto Project Proto with a CVSS 3.x base score of 5.6. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low.

Key facts

Severity: Medium (CVSS 3.x base score 5.6)
CVSS v2: 5.0
EPSS exploit prediction: 1% (54th percentile)
Actively exploited: Not listed in CISA KEV
Affected product: Proto Project Proto
Published: 2021-09-01
Last modified: 2026-06-17

Description

This affects all versions of package Proto. It is possible to inject pollute the object property of an application using Proto by leveraging the merge function.

Frequently asked questions

What is CVE-2021-23426?: This affects all versions of package Proto. It is possible to inject pollute the object property of an application using Proto by leveraging the merge function.
How severe is CVE-2021-23426?: CVE-2021-23426 has a CVSS 3.x base score of 5.6, rated medium severity. It is exploitable over network with high attack complexity, requires no privileges and no user interaction. Impact on confidentiality is low, integrity low, and availability low.
Is CVE-2021-23426 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (54th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-23426?: CVE-2021-23426 affects Proto Project Proto. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2021-23426?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2021-23426 published?: CVE-2021-23426 was published on 2021-09-01 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:proto_project:proto:-:*:*:*:*:node.js:*:*