How severe is CVE-2020-28940?

CVE-2020-28940 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-2020-28940 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 4% (89th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2020-28940?

CVE-2020-28940 affects Westerndigital My Cloud Os 5. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2020-28940?

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-2020-28940 published?

CVE-2020-28940 was published on 2020-12-01 and last updated on 2026-06-17.

CVE-2020-28940

CVE-2020-28940 is a critical-severity vulnerability in Westerndigital My Cloud Os 5 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-287.

Key facts

Severity: Critical (CVSS 3.x base score 9.8)
CVSS v2: 7.5
EPSS exploit prediction: 4% (89th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-287
Affected product: Westerndigital My Cloud Os 5
Published: 2020-12-01
Last modified: 2026-06-17

Description

On Western Digital My Cloud OS 5 devices before 5.06.115, the NAS Admin dashboard has an authentication bypass vulnerability that could allow an unauthenticated user to execute privileged commands on the device.

Frequently asked questions

What is CVE-2020-28940?: On Western Digital My Cloud OS 5 devices before 5.06.115, the NAS Admin dashboard has an authentication bypass vulnerability that could allow an unauthenticated user to execute privileged commands on the device.
How severe is CVE-2020-28940?: CVE-2020-28940 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-2020-28940 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 4% (89th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2020-28940?: CVE-2020-28940 affects Westerndigital My Cloud Os 5. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2020-28940?: 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-2020-28940 published?: CVE-2020-28940 was published on 2020-12-01 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:o:westerndigital:my_cloud_os_5:*:*:*:*:*:*:*:*

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Other CWE-287 (Improper Authentication) vulnerabilities

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CVE-2026-10611 — Critical (CVSS 10.0): An authentication bypass vulnerability exists in MISP when LDAP mixed authentication is enabled with OTP enforcement.…
CVE-2026-47280 — Critical (CVSS 10.0): Improper authentication in Azure Resource Manager (ARM) allows an unauthorized attacker to elevate privileges over a…
CVE-2026-42822 — Critical (CVSS 10.0): Improper authentication in Azure Local Disconnected Operations allows an unauthorized attacker to elevate privileges…
CVE-2026-20182 — Critical (CVSS 10.0): May 2026: This security advisory provides the details and fix information for a vulnerability that was discovered and…

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