How severe is CVE-2020-27888?

CVE-2020-27888 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity none, and availability none.

Is CVE-2020-27888 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (59th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2020-27888?

CVE-2020-27888 primarily affects Ui Unifi Meshing Access Point Firmware. In total, 2 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2020-27888?

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-2020-27888 published?

CVE-2020-27888 was published on 2020-10-27 and last updated on 2026-06-17.

CVE-2020-27888

CVE-2020-27888 is a high-severity vulnerability in Ui Unifi Meshing Access Point Firmware with a CVSS 3.x base score of 7.5. 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-459.

Key facts

Severity: High (CVSS 3.x base score 7.5)
CVSS v2: 5.0
EPSS exploit prediction: 1% (59th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-459
Affected product: Ui Unifi Meshing Access Point Firmware
Published: 2020-10-27
Last modified: 2026-06-17

Description

An issue was discovered on Ubiquiti UniFi Meshing Access Point UAP-AC-M 4.3.21.11325 and UniFi Controller 6.0.28 devices. Cached credentials are not erased from an access point returning wirelessly from a disconnected state. This may provide unintended network access.

Frequently asked questions

What is CVE-2020-27888?: An issue was discovered on Ubiquiti UniFi Meshing Access Point UAP-AC-M 4.3.21.11325 and UniFi Controller 6.0.28 devices. Cached credentials are not erased from an access point returning wirelessly from a disconnected state. This may provide unintended network access.
How severe is CVE-2020-27888?: CVE-2020-27888 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity none, and availability none.
Is CVE-2020-27888 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (59th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2020-27888?: CVE-2020-27888 primarily affects Ui Unifi Meshing Access Point Firmware. In total, 2 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2020-27888?: 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-2020-27888 published?: CVE-2020-27888 was published on 2020-10-27 and last updated on 2026-06-17.

References

https://community.ui.com/questions/Possible-authentication-bypass-for-access-into-LAN/7965adb2-5d70-4410-8467-4c7bec76bc00

Affected products (2)

cpe:2.3:o:ui:unifi_meshing_access_point_firmware:4.3.21.11325:*:*:*:*:*:*:*
cpe:2.3:o:ui:unifi_controller_firmware:6.0.28:*:*:*:*:*:*:*

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