CVE-2021-46521

Name: CVE-2021-46521
Creator: NVD / NIST
Published: 2022-01-27T21:15:09.99+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

HIGHCVSS 7.8/10EPSS 0.73%

Last modified Jun 17, 2026

CVE-2021-46521 is a high-severity vulnerability rated 7.8/10 on the CVSS scale. Cesanta MJS v2.20.0 was discovered to contain a global buffer overflow via c_vsnprintf at mjs/src/common/str_util.c.. EPSS estimates a 0.73% chance of exploitation in the next 30 days.

Description

Cesanta MJS v2.20.0 was discovered to contain a global buffer overflow via c_vsnprintf at mjs/src/common/str_util.c.

Metrics

CVSS 3.1

7.8/10

CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

EPSS Probability

0.73%

49.6th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-120

Affected Software

Vendor	Product	Versions
Cesanta	Mjs	2.20.0

References

https://github.com/cesanta/mjs/issues/190Exploit, Issue Tracking, Third Party Advisory
https://github.com/cesanta/mjs/issues/190Exploit, Issue Tracking, Third Party Advisory

Timeline

Published: Jan 27, 2022
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2021-46521?

Cesanta MJS v2.20.0 was discovered to contain a global buffer overflow via c_vsnprintf at mjs/src/common/str_util.c.

How severe is CVE-2021-46521?

CVE-2021-46521 has a CVSS score of 7.8/10 (HIGH severity). The EPSS model estimates a 0.73% probability of exploitation in the next 30 days.

How do I fix CVE-2021-46521?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2021-46521?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST