CVE-2025-66557

Name: CVE-2025-66557
Creator: NVD / NIST
Published: 2025-12-05T18:15:58.977+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

MEDIUMCVSS 4.3/10EPSS 0.23%

Last modified Jun 17, 2026

CVE-2025-66557 is a medium-severity vulnerability rated 4.3/10 on the CVSS scale. Nextcloud Deck is a kanban style organization tool aimed at personal planning and project organization for teams integrated with Nextcloud. Prior to 1.14.6 and 1.15.2, a bug in the permission logic allowed users with "Can share" permission to modify the permissions of other recipients. EPSS estimates a 0.23% chance of exploitation in the next 30 days.

Description

Nextcloud Deck is a kanban style organization tool aimed at personal planning and project organization for teams integrated with Nextcloud. Prior to 1.14.6 and 1.15.2, a bug in the permission logic allowed users with "Can share" permission to modify the permissions of other recipients. This vulnerability is fixed in 1.14.6 and 1.15.2.

Metrics

CVSS 3.1

4.3/10

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

EPSS Probability

0.23%

14.0th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-284

Affected Software

Vendor	Product	Versions
Nextcloud	Deck	>= 1.14.0, < 1.14.6
Nextcloud	Deck	>= 1.15.0, < 1.15.2

References

https://github.com/nextcloud/deck/commit/f1da8b30a455f02373d44154da04494c949a95aePatch
https://github.com/nextcloud/deck/pull/7131Issue Tracking, Patch
https://github.com/nextcloud/security-advisories/security/advisories/GHSA-wwr8-hx9g-rjvvPatch, Vendor Advisory
https://hackerone.com/reports/3247499Issue Tracking, Vendor Advisory

Timeline

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

Frequently Asked Questions

What is CVE-2025-66557?

How severe is CVE-2025-66557?

CVE-2025-66557 has a CVSS score of 4.3/10 (MEDIUM severity). The EPSS model estimates a 0.23% probability of exploitation in the next 30 days.

How do I fix CVE-2025-66557?

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-2025-66557?

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

Scan your code now

Source: NVD / NIST