How severe is CVE-2021-26738?

CVE-2021-26738 has a CVSS 3.x base score of 7.8, rated high severity. It is exploitable over local access with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2021-26738 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (14th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-26738?

CVE-2021-26738 affects Zscaler Client Connector. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2021-26738?

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

When was CVE-2021-26738 published?

CVE-2021-26738 was published on 2023-10-23 and last updated on 2026-06-17.

CVE-2021-26738

CVE-2021-26738 is a high-severity vulnerability in Zscaler Client Connector with a CVSS 3.x base score of 7.8. 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-426.

Key facts

Severity: High (CVSS 3.x base score 7.8)
EPSS exploit prediction: 0% (14th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-426
Affected product: Zscaler Client Connector
Published: 2023-10-23
Last modified: 2026-06-17

Description

Zscaler Client Connector for macOS prior to 3.7 had an unquoted search path vulnerability via the PATH variable. A local adversary may be able to execute code with root privileges.

Frequently asked questions

What is CVE-2021-26738?: Zscaler Client Connector for macOS prior to 3.7 had an unquoted search path vulnerability via the PATH variable. A local adversary may be able to execute code with root privileges.
How severe is CVE-2021-26738?: CVE-2021-26738 has a CVSS 3.x base score of 7.8, rated high severity. It is exploitable over local access with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2021-26738 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (14th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-26738?: CVE-2021-26738 affects Zscaler Client Connector. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2021-26738?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
When was CVE-2021-26738 published?: CVE-2021-26738 was published on 2023-10-23 and last updated on 2026-06-17.

References

https://help.zscaler.com/client-connector/client-connector-app-release-summary-2022?applicable_category=macOS&applicable_version=3.7&deployment_date=2022-08-19&id=1414851

Affected products (1)

cpe:2.3:a:zscaler:client_connector:*:*:*:*:*:macos:*:*

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