How severe is CVE-2020-26759?

CVE-2020-26759 has a CVSS 3.x base score of 9.8, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2020-26759 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 3% (83rd percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2020-26759?

CVE-2020-26759 affects Clickhouse-driver Project Clickhouse-driver. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2020-26759?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.

When was CVE-2020-26759 published?

CVE-2020-26759 was published on 2021-01-06 and last updated on 2026-06-17.

CVE-2020-26759

CVE-2020-26759 is a critical-severity vulnerability in Clickhouse-driver Project Clickhouse-driver with a CVSS 3.x base score of 9.8. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-120.

Key facts

Severity: Critical (CVSS 3.x base score 9.8)
CVSS v2: 7.5
EPSS exploit prediction: 3% (83rd percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-120
Affected product: Clickhouse-driver Project Clickhouse-driver
Published: 2021-01-06
Last modified: 2026-06-17

Description

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.

Frequently asked questions

What is CVE-2020-26759?: 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.
How severe is CVE-2020-26759?: CVE-2020-26759 has a CVSS 3.x base score of 9.8, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2020-26759 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 3% (83rd percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2020-26759?: CVE-2020-26759 affects Clickhouse-driver Project Clickhouse-driver. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2020-26759?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.
When was CVE-2020-26759 published?: CVE-2020-26759 was published on 2021-01-06 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:clickhouse-driver_project:clickhouse-driver:*:*:*:*:*:*:*:*

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