How severe is CVE-2021-23490?

CVE-2021-23490 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-2021-23490 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (76th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-23490?

CVE-2021-23490 affects Parse-link-header Project Parse-link-header. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2021-23490?

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-2021-23490 published?

CVE-2021-23490 was published on 2021-12-24 and last updated on 2026-06-17.

CVE-2021-23490

CVE-2021-23490 is a high-severity vulnerability in Parse-link-header Project Parse-link-header 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-1333.

Key facts

Severity: High (CVSS 3.x base score 7.5)
CVSS v2: 5.0
EPSS exploit prediction: 2% (76th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-1333
Affected product: Parse-link-header Project Parse-link-header
Published: 2021-12-24
Last modified: 2026-06-17

Description

The package parse-link-header before 2.0.0 are vulnerable to Regular Expression Denial of Service (ReDoS) via the checkHeader function.

Frequently asked questions

What is CVE-2021-23490?: The package parse-link-header before 2.0.0 are vulnerable to Regular Expression Denial of Service (ReDoS) via the checkHeader function.
How severe is CVE-2021-23490?: CVE-2021-23490 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-2021-23490 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (76th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-23490?: CVE-2021-23490 affects Parse-link-header Project Parse-link-header. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2021-23490?: 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-2021-23490 published?: CVE-2021-23490 was published on 2021-12-24 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:parse-link-header_project:parse-link-header:*:*:*:*:*:node.js:*:*

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