CVE-2020-26759

CRITICALNVD 9.89.8—

9.8

clickhouse-driver before 0.1.5 allows a malicious clickhouse server to trigger a crash or execute arbitrary code (on a database client) via a crafted server response, due to a buffer overflow.

CVSS v3: 9.8
EG Score: 9.8(medium)
EPSS: 87.0%
KEV: Not listed

Published

January 6, 2021

Last Modified

November 21, 2024

Advisory Details (2)

Auto-updated May 26, 2026

Upstream fix merged — awaiting tagged release. Sources: github_commit.

github_commit

commit d708ed548e1d (mymarilyn/clickhouse-driver)

Fix landed in mymarilyn/clickhouse-driver commit d708ed548e1d — awaiting tagged release

https://github.com/mymarilyn/clickhouse-driver/commit/d708ed548e1d6f254ba81a21de8ba543a53b5598

github_commit

commit 3e990547e064 (mymarilyn/clickhouse-driver)

Fix landed in mymarilyn/clickhouse-driver commit 3e990547e064 — awaiting tagged release

https://github.com/mymarilyn/clickhouse-driver/commit/3e990547e064b8fca916b23a0f7d6fe8c63c7f6b

Affected Packages

(1 across 1 ecosystem)

PyPI(1)

Package	Vulnerable range	Fixed in	Dependents
clickhouse-driver	0.0.2 ... 0.1.4 (24 versions)	0.1.5	—

Weakness Classification(1)

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

CWE-120Buffer Copy without Checking Size (Classic Buffer Overflow)

Data Freshness Timeline

(refreshed 6× in last 7d / 6× 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.

2026-05-27 13:39 UTCepss_batch
2026-05-27 13:39 UTCepss_batch
2026-05-26 22:36 UTCEG score recompute
2026-05-26 11:45 UTCOSV refresh
2026-05-26 07:17 UTCepss_batch
2026-05-26 07:17 UTCepss_batch

Frequently asked(5)

What is CVE-2020-26759?

CVE-2020-26759 is a critical vulnerability published on January 6, 2021. clickhouse-driver before 0.1.5 allows a malicious clickhouse server to trigger a crash or execute arbitrary code (on a database client) via a crafted server response, due to a buffer overflow.

When was CVE-2020-26759 disclosed?

CVE-2020-26759 was first published in the National Vulnerability Database on January 6, 2021, 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-2020-26759 actively exploited?

CVE-2020-26759 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 87.0% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.

What is the CVSS score of CVE-2020-26759?

CVE-2020-26759 has a CVSS v3 base score of 9.8 (NVD).

How do I remediate CVE-2020-26759?

Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2020-26759, 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

See which npm, PyPI, Go, and Maven packages are affected by CVE-2020-26759

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