How severe is CVE-2025-66549?

CVE-2025-66549 has a CVSS 3.x base score of 2.4, rated low severity. It is exploitable over network with low attack complexity, requires high privileges and user interaction. Impact on confidentiality is low, integrity none, and availability none.

Is CVE-2025-66549 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (16th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2025-66549?

CVE-2025-66549 affects Nextcloud Desktop. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2025-66549?

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

Does CVE-2025-66549 have an EU (EUVD) identifier?

Yes. CVE-2025-66549 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2025-201462.

When was CVE-2025-66549 published?

CVE-2025-66549 was published on 2025-12-05 and last updated on 2026-06-17.

CVE-2025-66549

CVE-2025-66549 is a low-severity vulnerability in Nextcloud Desktop with a CVSS 3.x base score of 2.4. 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-209.

Key facts

Severity: Low (CVSS 3.x base score 2.4)
EPSS exploit prediction: 0% (16th percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2025-201462
Weakness: CWE-209
Affected product: Nextcloud Desktop
Published: 2025-12-05
Last modified: 2026-06-17

Description

Nextcloud Desktop is the desktop sync client for Nextcloud. Prior to 3.16.5, when trying to manually lock a file inside an end-to-end encrypted directory, the path of the file was sent to the server unencrypted, making it possible for administrators to see it in log files. This vulnerability is fixed in 3.16.5.

Frequently asked questions

What is CVE-2025-66549?: Nextcloud Desktop is the desktop sync client for Nextcloud. Prior to 3.16.5, when trying to manually lock a file inside an end-to-end encrypted directory, the path of the file was sent to the server unencrypted, making it possible for administrators to see it in log files. This vulnerability is fixed in 3.16.5.
How severe is CVE-2025-66549?: CVE-2025-66549 has a CVSS 3.x base score of 2.4, rated low severity. It is exploitable over network with low attack complexity, requires high privileges and user interaction. Impact on confidentiality is low, integrity none, and availability none.
Is CVE-2025-66549 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (16th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2025-66549?: CVE-2025-66549 affects Nextcloud Desktop. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2025-66549?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
Does CVE-2025-66549 have an EU (EUVD) identifier?: Yes. CVE-2025-66549 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2025-201462.
When was CVE-2025-66549 published?: CVE-2025-66549 was published on 2025-12-05 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:nextcloud:desktop:*:*:*:*:*:*:*:*

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