CVE-2025-66548

Nextcloud Deck is a kanban style organization tool aimed at personal planning and project organization for teams integrated with Nextcloud. Prior to 1.12.7, 1.14.4, and 1.15.1, file extension can be spoofed by using RTLO characters, tricking users into download files with a different extension than what is displayed. This vulnerability is fixed in 1.12.7, 1.14.4, and 1.15.1.

CVSS 3.1

5.5CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N

EPSS

0.2% chance of exploitation in the next 30 days; higher than 4% of CVEs (scores of 2026-10-25)

CWE

CWE-116

Published

2025-12-05

Modified

2026-10-15

Record from

the NVD, synced 2026-10-19

Affected

• nextcloud:deck

References

• https://github.com/nextcloud/deck/commit/afa95d3c507465b9d31af7c88c69b76711ef185a
• https://github.com/nextcloud/deck/pull/6671
• https://github.com/nextcloud/security-advisories/security/advisories/GHSA-xjvq-xvr7-xpg6
• https://hackerone.com/reports/2326618

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