Vulnerability Report

CVE-2025-66548

Title: Nextcloud Deck File Extension Spoofing

Other

Proof Of Concept

No public PoC currently indexed for CVE-2025-66548.

CWE Category CWE-116
Published Date Dec 05, 2025
Modified Date Oct 15, 2026
Exploit Status Not Found
Score 3.3 CVSS v3.1
Exploit Probability (EPSS)
0.15%

Vulnerability Summary

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.

Impacted Vendors

N
nextcloud 1

Reference Links

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
CVSS v3.1
Source Entity [email protected]
Severity LOW
3.3
Attack Vector
LOCAL
Complexity
LOW
Privileges
N/A
Interaction
NONE
Confidentiality
N/A
Integrity
N/A
Availability
N/A
Scope
UNCHANGED
RAW VECTOR CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N
CVSS v3.1
Source Entity [email protected]
Severity MEDIUM
5.5
Attack Vector
LOCAL
Complexity
LOW
Privileges
N/A
Interaction
REQUIRED
Confidentiality
N/A
Integrity
N/A
Availability
N/A
Scope
UNCHANGED
RAW VECTOR CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N

Associated Attack Patterns (CAPEC)

Total: Patterns

CVE-2025-66548 Exploits & PoCs (Proof Of Concept)

No public PoCs found in our database for this CVE.

MODIFIED

Vulnerability data updated via NVD.

MODIFIED

Vulnerability data or affected products updated.

MODIFIED

Vulnerability data updated via NVD.

PUBLISHED

Vulnerability first announced in NVD.

Attack Vector Matrix

Access Vector LOCAL
Complexity LOW
Privileges N/A
Interaction NONE
CVSS Vector String CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N

Affected Stack

No specific products linked.