How severe is CVE-2021-33587?

CVE-2021-33587 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-2021-33587 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (81st percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-33587?

CVE-2021-33587 primarily affects Css-what Project Css-what. In total, 3 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2021-33587?

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-2021-33587 published?

CVE-2021-33587 was published on 2021-05-28 and last updated on 2026-06-17.

CVE-2021-33587

CVE-2021-33587 is a high-severity vulnerability in Css-what Project Css-what 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.

Key facts

Severity: High (CVSS 3.x base score 7.5)
CVSS v2: 5.0
EPSS exploit prediction: 2% (81st percentile)
Actively exploited: Not listed in CISA KEV
Affected product: Css-what Project Css-what
Published: 2021-05-28
Last modified: 2026-06-17

Description

The css-what package 4.0.0 through 5.0.0 for Node.js does not ensure that attribute parsing has Linear Time Complexity relative to the size of the input.

Frequently asked questions

What is CVE-2021-33587?: The css-what package 4.0.0 through 5.0.0 for Node.js does not ensure that attribute parsing has Linear Time Complexity relative to the size of the input.
How severe is CVE-2021-33587?: CVE-2021-33587 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-2021-33587 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (81st percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-33587?: CVE-2021-33587 primarily affects Css-what Project Css-what. In total, 3 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2021-33587?: 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-2021-33587 published?: CVE-2021-33587 was published on 2021-05-28 and last updated on 2026-06-17.

References

Affected products (3)

cpe:2.3:a:css-what_project:css-what:4.0.0:*:*:*:*:node.js:*:*
cpe:2.3:a:css-what_project:css-what:5.0.0:*:*:*:*:node.js:*:*
cpe:2.3:a:netapp:e-series_performance_analyzer:-:*:*:*:*:*:*:*

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