How severe is CVE-2023-28999?

CVE-2023-28999 has a CVSS 3.x base score of 6.9, rated medium severity. It is exploitable over physical access with low attack complexity, requires high privileges and user interaction. Impact on confidentiality is high, integrity high, and availability low.

Is CVE-2023-28999 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (48th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2023-28999?

CVE-2023-28999 primarily affects Nextcloud Desktop. In total, 3 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2023-28999?

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

When was CVE-2023-28999 published?

CVE-2023-28999 was published on 2023-04-04 and last updated on 2026-06-17.

CVE-2023-28999

CVE-2023-28999 is a medium-severity vulnerability in Nextcloud Desktop with a CVSS 3.x base score of 6.9. 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-311.

Key facts

Severity: Medium (CVSS 3.x base score 6.9)
EPSS exploit prediction: 1% (48th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-311
Affected product: Nextcloud Desktop
Published: 2023-04-04
Last modified: 2026-06-17

Description

Nextcloud is an open-source productivity platform. In Nextcloud Desktop client 3.0.0 until 3.8.0, Nextcloud Android app 3.13.0 until 3.25.0, and Nextcloud iOS app 3.0.5 until 4.8.0, a malicious server administrator can gain full access to an end-to-end encrypted folder. They can decrypt files, recover the folder structure and add new files. This issue is fixed in Nextcloud Desktop 3.8.0, Nextcloud Android 3.25.0, and Nextcloud iOS 4.8.0. No known workarounds are available.

Frequently asked questions

What is CVE-2023-28999?: Nextcloud is an open-source productivity platform. In Nextcloud Desktop client 3.0.0 until 3.8.0, Nextcloud Android app 3.13.0 until 3.25.0, and Nextcloud iOS app 3.0.5 until 4.8.0, a malicious server administrator can gain full access to an end-to-end encrypted folder. They can decrypt files, recover the folder structure and add new files. This issue is fixed in Nextcloud Desktop 3.8.0, Nextcloud Android 3.25.0, and Nextcloud iOS 4.8.0. No known workarounds are available.
How severe is CVE-2023-28999?: CVE-2023-28999 has a CVSS 3.x base score of 6.9, rated medium severity. It is exploitable over physical access with low attack complexity, requires high privileges and user interaction. Impact on confidentiality is high, integrity high, and availability low.
Is CVE-2023-28999 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (48th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2023-28999?: CVE-2023-28999 primarily affects Nextcloud Desktop. In total, 3 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2023-28999?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2023-28999 published?: CVE-2023-28999 was published on 2023-04-04 and last updated on 2026-06-17.

References

Affected products (3)

cpe:2.3:a:nextcloud:desktop:*:*:*:*:*:*:*:*
cpe:2.3:a:nextcloud:nextcloud:*:*:*:*:iphone_os:*:*:*
cpe:2.3:a:nextcloud:nextcloud:*:*:*:*:android:*:*:*

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