CVE-2025-66549

Name: CVE-2025-66549
Creator: NVD / NIST
Published: 2025-12-05T18:15:58.133+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

LOWCVSS 2.7/10EPSS 0.24%

Last modified Jun 17, 2026

CVE-2025-66549 is a low-severity vulnerability rated 2.7/10 on the CVSS scale. 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. EPSS estimates a 0.24% chance of exploitation in the next 30 days.

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.

Metrics

CVSS 3.1

2.7/10

CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:L/I:N/A:N

EPSS Probability

0.24%

15.2th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-209

Affected Software

Vendor	Product	Versions
Nextcloud	Desktop	>= 3.0.0, < 3.16.5

References

https://github.com/nextcloud/desktop/commit/36d6c234d42b06a6f2e9de3e413a5c3c625edad6Patch
https://github.com/nextcloud/desktop/pull/8330Issue Tracking
https://github.com/nextcloud/security-advisories/security/advisories/GHSA-h9xj-qh76-q3hwPatch, Vendor Advisory
https://hackerone.com/reports/3159877Permissions Required, Vendor Advisory

Timeline

Published: Dec 5, 2025
Last Modified: Jun 17, 2026
Status: Analyzed

Frequently Asked Questions

What is CVE-2025-66549?

How severe is CVE-2025-66549?

CVE-2025-66549 has a CVSS score of 2.7/10 (LOW severity). The EPSS model estimates a 0.24% probability of exploitation in the next 30 days.

How do I fix CVE-2025-66549?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2025-66549?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST