CVE-2021-33437

MEDIUMNVD 5.55.5—

5.5

An issue was discovered in mjs (mJS: Restricted JavaScript engine), ES6 (JavaScript version 6). There are memory leaks in frozen_cb() in mjs.c.

CVSS v3: 5.5
EG Score: 5.5(medium)
EPSS: 14.6%
KEV: Not listed

Published

July 26, 2022

Last Modified

November 21, 2024

References (4)

cve@mitrehttps://gist.github.com/Clingto/bb632c0c463f4b2c97e4f65f751c5e6d
cve@mitrehttps://github.com/cesanta/mjs/issues/160
af854a3a-2127-422b-91ae-364da2661108https://gist.github.com/Clingto/bb632c0c463f4b2c97e4f65f751c5e6d
af854a3a-2127-422b-91ae-364da2661108https://github.com/cesanta/mjs/issues/160

Weakness Classification(2)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

Data Freshness Timeline

(refreshed 12× in last 7d / 20× in last 30d)

Every time one of our enrichment pipelines (NVD, MITRE cvelistV5, EPSS, CISA KEV, GHSA, OSV, vendor advisories) ran against this CVE. Most recent first.

2026-06-02 20:11 UTCepss_batch
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2026-06-01 13:50 UTCepss_batch
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2026-05-29 13:42 UTCepss_batch
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2026-05-28 13:43 UTCepss_batch
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2026-05-27 13:39 UTCepss_batch
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2026-05-26 07:17 UTCepss_batch
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2026-05-26 07:17 UTCepss_batch
2026-05-25 18:19 UTCEG score recompute

Frequently asked(5)

What is CVE-2021-33437?

CVE-2021-33437 is a medium vulnerability published on July 26, 2022. An issue was discovered in mjs (mJS: Restricted JavaScript engine), ES6 (JavaScript version 6). There are memory leaks in frozen_cb() in mjs.c.

When was CVE-2021-33437 disclosed?

CVE-2021-33437 was first published in the National Vulnerability Database on July 26, 2022, with the most recent update on November 21, 2024. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.

Is CVE-2021-33437 actively exploited?

CVE-2021-33437 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 14.6% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.

What is the CVSS score of CVE-2021-33437?

CVE-2021-33437 has a CVSS v3 base score of 5.5 (NVD).

How do I remediate CVE-2021-33437?

Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2021-33437, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

Dependency Blast Radius

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CVE-2021-33437

📅 Published

🔄 Last Modified

🔗 References (4)

Weakness Classification(2)

Data Freshness Timeline

❓ Frequently asked(5)

Dependency Blast Radius

Is Your Infrastructure Affected by CVE-2021-33437?

🔗 Related CVEs(same CWE)

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Published

Last Modified

References (4)

Frequently asked(5)

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