How severe is CVE-2021-21267?

CVE-2021-21267 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.

Is CVE-2021-21267 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (79th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-21267?

CVE-2021-21267 primarily affects Schema-inspector Project Schema-inspector. In total, 3 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2021-21267?

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

When was CVE-2021-21267 published?

CVE-2021-21267 was published on 2021-03-19 and last updated on 2026-06-17.

CVE-2021-21267

CVE-2021-21267 is a high-severity vulnerability in Schema-inspector Project Schema-inspector with a CVSS 3.x base score of 7.5. 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-20.

Key facts

Severity: High (CVSS 3.x base score 7.5)
CVSS v2: 5.0
EPSS exploit prediction: 2% (79th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-20
Affected product: Schema-inspector Project Schema-inspector
Published: 2021-03-19
Last modified: 2026-06-17

Description

Schema-Inspector is an open-source tool to sanitize and validate JS objects (npm package schema-inspector). In before version 2.0.0, email address validation is vulnerable to a denial-of-service attack where some input (for example `a@0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.`) will freeze the program or web browser page executing the code. This affects any current schema-inspector users using any version to validate email addresses. Users who do not do email validation, and instead do other types of validation (like string min or max length, etc), are not affected. Users should upgrade to version 2.0.0, which uses a regex expression that isn't vulnerable to ReDoS.

Frequently asked questions

What is CVE-2021-21267?: Schema-Inspector is an open-source tool to sanitize and validate JS objects (npm package schema-inspector). In before version 2.0.0, email address validation is vulnerable to a denial-of-service attack where some input (for example `a@0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.`) will freeze the program or web browser page executing the code. This affects any current schema-inspector users using any version to validate email addresses. Users who do not do email validation, and instead do other types of validation (like string min or max length, etc), are not affected. Users should upgrade to version 2.0.0, which uses a regex expression that isn't vulnerable to ReDoS.
How severe is CVE-2021-21267?: CVE-2021-21267 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.
Is CVE-2021-21267 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (79th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-21267?: CVE-2021-21267 primarily affects Schema-inspector Project Schema-inspector. In total, 3 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2021-21267?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
When was CVE-2021-21267 published?: CVE-2021-21267 was published on 2021-03-19 and last updated on 2026-06-17.

References

Affected products (3)

cpe:2.3:a:schema-inspector_project:schema-inspector:*:*:*:*:*:node.js:*:*
cpe:2.3:a:netapp:e-series_performance_analyzer:-:*:*:*:*:*:*:*
cpe:2.3:a:netapp:oncommand_insight:-:*:*:*:*:*:*:*

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