How severe is CVE-2020-26302?

CVE-2020-26302 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-2020-26302 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-2020-26302?

CVE-2020-26302 affects Is.js Project Is.js. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2020-26302?

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-2020-26302 published?

CVE-2020-26302 was published on 2022-12-22 and last updated on 2026-06-17.

CVE-2020-26302

CVE-2020-26302 is a high-severity vulnerability in Is.js Project Is.js 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)
EPSS exploit prediction: 1% (54th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-1333
Affected product: Is.js Project Is.js
Published: 2022-12-22
Last modified: 2026-06-17

Description

is.js is a general-purpose check library. Versions 0.9.0 and prior contain one or more regular expressions that are vulnerable to Regular Expression Denial of Service (ReDoS). is.js uses a regex copy-pasted from a gist to validate URLs. Trying to validate a malicious string can cause the regex to loop “forever." This vulnerability was found using a CodeQL query which identifies inefficient regular expressions. is.js has no patch for this issue.

Frequently asked questions

What is CVE-2020-26302?: is.js is a general-purpose check library. Versions 0.9.0 and prior contain one or more regular expressions that are vulnerable to Regular Expression Denial of Service (ReDoS). is.js uses a regex copy-pasted from a gist to validate URLs. Trying to validate a malicious string can cause the regex to loop “forever." This vulnerability was found using a CodeQL query which identifies inefficient regular expressions. is.js has no patch for this issue.
How severe is CVE-2020-26302?: CVE-2020-26302 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-2020-26302 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-2020-26302?: CVE-2020-26302 affects Is.js Project Is.js. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2020-26302?: 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-2020-26302 published?: CVE-2020-26302 was published on 2022-12-22 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:is.js_project:is.js:*:*:*:*:*:*:*:*

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