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CVE-2020-26302

Status: ModifiedHigh (7.5)—
Severity7.5High · CVSS 3.1
Exploitation probability0.89 %higher than 59% of CVEs
Active exploitationNonot in the CISA catalog
Public exploitNot knownno public code found

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.

CVSS

Base score
7.5
Version
3.1
Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Exploitation probability (EPSS)

Probability of exploitation in the next 30 days
0.89 %
Percentile among all scored CVEs
59
Score date
10/21/2026

EPSS (Exploit Prediction Scoring System, FIRST) estimates how likely a vulnerability is to be exploited in the wild within 30 days. It complements CVSS (impact) and CISA KEV (confirmed exploitation).

Affected technologies (1)

Is.js Project — Is.js

CWEs

References

Show 4 references

Raw JSON (NVD)

Show
{
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          "options": [
            {
              "exploitation": "poc"
            },
            {
              "automatable": "yes"
            },
            {
              "technicalImpact": "partial"
            }
          ],
          "version": "2.0.3",
          "timestamp": "2025-04-14T14:36:57.552001Z"
        }
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          "integrityImpact": "NONE",
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  "vulnStatus": "Modified",
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      "description": [
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          "value": "CWE-1333"
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  ],
  "descriptions": [
    {
      "lang": "en",
      "value": "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."
    },
    {
      "lang": "es",
      "value": "is.js es una librería de verificación de uso general. Las versiones 0.9.0 y anteriores contienen una o más expresiones regulares que son vulnerables a la denegación de servicio de expresión regular (ReDoS). is.js utiliza una expresión regular copiada y pegada de una esencia para validar las URL. Intentar validar una cadena maliciosa puede hacer que la expresión regular se repita \"forever\". Esta vulnerabilidad se encontró mediante una consulta CodeQL que identifica expresiones regulares ineficientes. is.js no tiene ningún parche para este problema."
    }
  ],
  "lastModified": "2026-06-17T03:08:02.120",
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}