What is CVE-2021-46556?

CVE-2021-46556 is a medium-severity vulnerability in Cesanta Mjs. CVSS score: 5.5/10. Published 2022-01-27.

How severe is CVE-2021-46556?

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

Vulnerability in Cesanta Mjs

CVE-2021-46556

Cesanta MJS v2.20.0 was discovered to contain a SEGV vulnerability via mjs_bcode_insert_offset at src/mjs_bcode.c. This vulnerability can lead to a Denial of Service (DoS).

Published 2022-01-27 · last modified 2026-06-17.

CVSS v3 metric

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

EPSS exploit prediction

EPSS: 0.006 (47.7th percentile), scored 2026-09-29.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 48th percentile — 47.7% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.006 · newest: 0.006 · change: 0.000

Affected products

Cesanta Mjs — versions 2.20.0

References

github.com/cesanta/mjs/issues/227 (Exploit, Patch, Third Party Advisory, Issue Tracking)

Frequently asked questions

What is CVE-2021-46556?: CVE-2021-46556 is a medium-severity vulnerability in Cesanta Mjs. CVSS score: 5.5/10. Published 2022-01-27.
How severe is CVE-2021-46556?: Medium severity. CVSS v3 base score is 5.5 out of 10.