CVE-2021-42390

MEDIUMNVD 6.56.5—

6.5

Divide-by-zero in Clickhouse's DeltaDouble compression codec when parsing a malicious query. The first byte of the compressed buffer is used in a modulo operation without being checked for 0.

CVSS v3: 6.5
EG Score: 6.5(medium)
EPSS: 68.3%
KEV: Not listed

Published

March 14, 2022

Last Modified

June 25, 2025

References (2)

reefs@jfroghttps://jfrog.com/blog/7-rce-and-dos-vulnerabilities-found-in-clickhouse-dbms
af854a3a-2127-422b-91ae-364da2661108https://jfrog.com/blog/7-rce-and-dos-vulnerabilities-found-in-clickhouse-dbms

Weakness Classification(1)

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

CWE-369Divide By Zero

Data Freshness Timeline

(refreshed 11× 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
2026-06-02 20:11 UTCepss_batch
2026-06-01 13:50 UTCepss_batch
2026-06-01 13:50 UTCepss_batch
2026-05-31 22:29 UTCepss_batch
2026-05-31 22:29 UTCepss_batch
2026-05-31 00:15 UTCepss_batch
2026-05-31 00:15 UTCepss_batch
2026-05-29 13:42 UTCepss_batch
2026-05-28 13:43 UTCepss_batch
2026-05-28 13:43 UTCepss_batch
2026-05-27 13:39 UTCepss_batch
2026-05-27 13:39 UTCepss_batch
2026-05-26 13:42 UTCepss_batch
2026-05-26 13:42 UTCepss_batch
2026-05-26 07:17 UTCepss_batch
2026-05-26 07:17 UTCepss_batch
2026-05-26 07:17 UTCepss_batch
2026-05-26 01:39 UTCEG score recompute
2026-05-26 01:39 UTCGHSA enrichment

Frequently asked(5)

What is CVE-2021-42390?

CVE-2021-42390 is a medium vulnerability published on March 14, 2022. Divide-by-zero in Clickhouse's DeltaDouble compression codec when parsing a malicious query. The first byte of the compressed buffer is used in a modulo operation without being checked for 0.

When was CVE-2021-42390 disclosed?

CVE-2021-42390 was first published in the National Vulnerability Database on March 14, 2022, with the most recent update on June 25, 2025. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.

Is CVE-2021-42390 actively exploited?

CVE-2021-42390 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 68.3% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.

What is the CVSS score of CVE-2021-42390?

CVE-2021-42390 has a CVSS v3 base score of 6.5 (NVD).

How do I remediate CVE-2021-42390?

Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2021-42390, 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-2021-42390

📅 Published

🔄 Last Modified

🔗 References (2)

Weakness Classification(1)

Data Freshness Timeline

❓ Frequently asked(5)

Dependency Blast Radius

Is Your Infrastructure Affected by CVE-2021-42390?

🔗 Related CVEs(same CWE)

Same CWE

Published

Last Modified

References (2)

Frequently asked(5)

Related CVEs(same CWE)