PT-2025-49297 · Nextcloud · Nextcloud Deck

Published 2025-12-05 · Updated 2025-12-09 · CVE-2025-66548

Positive Technologies (AI Summary)

CVSS v3.1

5.5

Medium

Base vector

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

Name of the Vulnerable Software and Affected Versions Nextcloud Deck versions prior to 1.12.7 Nextcloud Deck versions prior to 1.14.4 Nextcloud Deck versions prior to 1.15.1

Description Nextcloud Deck is a kanban style organization tool for personal planning and project organization integrated with Nextcloud. Prior to versions 1.12.7, 1.14.4, and 1.15.1, a file extension can be manipulated using RTLO characters, potentially misleading users into downloading files with an unexpected extension.

Recommendations Update Nextcloud Deck to version 1.12.7 or later. Update Nextcloud Deck to version 1.14.4 or later. Update Nextcloud Deck to version 1.15.1 or later.

Exploit

Fix

Improper Encoding or Escaping of Output

Weakness Enumeration

CWE-116

Related Identifiers

CVE-2025-66548

GHSA-XJVQ-XVR7-XPG6

Affected Products

Nextcloud Deck

References · 10

• 🔥 https://github.com/CVEProject/cvelistV5/tree/main/cves/2025/66xxx/CVE-2025-66548.json · Exploit
• https://github.com/nextcloud/deck/commit/afa95d3c507465b9d31af7c88c69b76711ef185a · Patch
• https://github.com/nextcloud/security-advisories/security/advisories/GHSA-xjvq-xvr7-xpg6 · Vendor Advisory
• https://hackerone.com/reports/2326618 · Vendor Advisory
• https://osv.dev/vulnerability/CVE-2025-66548 · Vendor Advisory
• https://nvd.nist.gov/vuln/detail/CVE-2025-66548 · Security Note
• https://github.com/nextcloud/deck/pull/6671 · Note
• https://twitter.com/dailycve/status/1998515542949527917 · Twitter Post
• https://t.me/CVEtracker/38947 · Telegram Post
• https://twitter.com/CVEnew/status/1997000967556862298 · Twitter Post