How severe is CVE-2021-22877?

CVE-2021-22877 has a CVSS 3.x base score of 6.5, rated medium severity. It is exploitable over network with low attack complexity, requires high privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability none.

Is CVE-2021-22877 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (76th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-22877?

CVE-2021-22877 primarily affects Nextcloud Nextcloud Server. In total, 2 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2021-22877?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

When was CVE-2021-22877 published?

CVE-2021-22877 was published on 2021-03-03 and last updated on 2026-06-17.

CVE-2021-22877

CVE-2021-22877 is a medium-severity vulnerability in Nextcloud Nextcloud Server with a CVSS 3.x base score of 6.5. 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-862.

Key facts

Severity: Medium (CVSS 3.x base score 6.5)
CVSS v2: 5.5
EPSS exploit prediction: 2% (76th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-862
Affected product: Nextcloud Nextcloud Server
Published: 2021-03-03
Last modified: 2026-06-17

Description

A missing user check in Nextcloud prior to 20.0.6 inadvertently populates a user's own credentials for other users external storage configuration when not already configured yet.

Frequently asked questions

What is CVE-2021-22877?: A missing user check in Nextcloud prior to 20.0.6 inadvertently populates a user's own credentials for other users external storage configuration when not already configured yet.
How severe is CVE-2021-22877?: CVE-2021-22877 has a CVSS 3.x base score of 6.5, rated medium severity. It is exploitable over network with low attack complexity, requires high privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability none.
Is CVE-2021-22877 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (76th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-22877?: CVE-2021-22877 primarily affects Nextcloud Nextcloud Server. In total, 2 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2021-22877?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2021-22877 published?: CVE-2021-22877 was published on 2021-03-03 and last updated on 2026-06-17.

References

Affected products (2)

cpe:2.3:a:nextcloud:nextcloud_server:*:*:*:*:*:*:*:*
cpe:2.3:o:fedoraproject:fedora:34:*:*:*:*:*:*:*

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