How severe is CVE-2021-27259?

CVE-2021-27259 has a CVSS 3.x base score of 7.8, rated high severity. It is exploitable over local access with high attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2021-27259 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (36th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-27259?

CVE-2021-27259 affects Parallels Parallels Desktop. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2021-27259?

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-2021-27259 published?

CVE-2021-27259 was published on 2021-04-14 and last updated on 2026-06-17.

CVE-2021-27259

CVE-2021-27259 is a high-severity vulnerability in Parallels Parallels Desktop 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-190.

Key facts

Severity: High (CVSS 3.x base score 7.8)
CVSS v2: 4.4
EPSS exploit prediction: 0% (36th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-190
Affected product: Parallels Parallels Desktop
Published: 2021-04-14
Last modified: 2026-06-17

Description

This vulnerability allows local attackers to escalate privileges on affected installations of Parallels Desktop 16.0.1-48919. An attacker must first obtain the ability to execute low-privileged code on the target guest system in order to exploit this vulnerability. The specific flaw exists within the Toolgate component. The issue results from the lack of proper validation of user-supplied data, which can result in an integer overflow before allocating a buffer. An attacker can leverage this vulnerability to escalate privileges and execute arbitrary code in the context of the hypervisor. Was ZDI-CAN-12021.

Frequently asked questions

What is CVE-2021-27259?: This vulnerability allows local attackers to escalate privileges on affected installations of Parallels Desktop 16.0.1-48919. An attacker must first obtain the ability to execute low-privileged code on the target guest system in order to exploit this vulnerability. The specific flaw exists within the Toolgate component. The issue results from the lack of proper validation of user-supplied data, which can result in an integer overflow before allocating a buffer. An attacker can leverage this vulnerability to escalate privileges and execute arbitrary code in the context of the hypervisor. Was ZDI-CAN-12021.
How severe is CVE-2021-27259?: CVE-2021-27259 has a CVSS 3.x base score of 7.8, rated high severity. It is exploitable over local access with high attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2021-27259 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (36th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-27259?: CVE-2021-27259 affects Parallels Parallels Desktop. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2021-27259?: 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-2021-27259 published?: CVE-2021-27259 was published on 2021-04-14 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:parallels:parallels_desktop:16.0.1:*:*:*:*:macos:*:*

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