CVE-2020-7777
CVSS v3
7.2
HIGH
EPSS Score
2.1 %
exploit probability, as of 2026-09-25
CISA KEV
No
known exploited
Exploitation
—
SSVC status
Description
This affects all versions of package jsen. If an attacker can control the schema file, it could run arbitrary JavaScript code on the victim machine. In the module description and README file there is no mention about the risks of untrusted schema files, so I assume that this is applicable. In particular the required field of the schema is not properly sanitized. The resulting string that is build based on the schema definition is then passed to a Function.apply();, leading to an Arbitrary Code Execution.
Technical details
- Published
- 2020-11-23
Frequently asked questions
What is CVE-2020-7777?
This affects all versions of package jsen. If an attacker can control the schema file, it could run arbitrary JavaScript code on the victim machine. In the module description and README file there is no mention about the risks of untrusted schema files, so I assume that this is applicable. In particular the required field of the schema is not properly sanitized. The resulting string that is build based on the schema definition is then passed to a Function.apply();, leading to an Arbitrary Code Execution.
Is CVE-2020-7777 actively exploited?
Active exploitation of CVE-2020-7777 has not been confirmed. Its EPSS score was 2.1% on 2026-09-25, the estimated probability of exploitation in the next 30 days.
What is the CVSS score for CVE-2020-7777?
CVE-2020-7777 has a CVSS v3 base score of 7.2 (HIGH severity).
Is CVE-2020-7777 affecting your environment?
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