What is CVE-2021-36535?

CVE-2021-36535 is a medium-severity vulnerability in Cesanta Mjs, classified under Out-of-bounds Write. CVSS score: 5.5/10. Published 2023-02-03.

How severe is CVE-2021-36535?

Medium severity. CVSS v3 base score is 5.5 out of 10.

Buffer overflow in Cesanta Mjs

CVE-2021-36535

Buffer Overflow vulnerability in Cesanta mJS 1.26 allows remote attackers to cause a denial of service via crafted .js file to mjs_set_errorf.

Vulnerability class: Buffer Overflow

Published 2023-02-03 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 5.5 (Medium). Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H.

EPSS exploit prediction

EPSS: 0.004 (28.6th percentile), scored 2026-09-29.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 29th percentile — 28.6% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.004 · newest: 0.004 · change: 0.000

Affected products

Cesanta Mjs — versions 1.26

Weakness classification (CWE)

CWE-787 — Out-of-bounds Write

References

github.com/cesanta/mjs/issues/175 (Exploit, Third Party Advisory, Issue Tracking)

Frequently asked questions

What is CVE-2021-36535?: CVE-2021-36535 is a medium-severity vulnerability in Cesanta Mjs, classified under Out-of-bounds Write. CVSS score: 5.5/10. Published 2023-02-03.
How severe is CVE-2021-36535?: Medium severity. CVSS v3 base score is 5.5 out of 10.