Low 3.3Published Dec 5, 2025

CVE-2025-66548Nextcloud Deck app allows to spoof file extensions by using RTLO characters

Updated under an hour ago (Oct 26, 2026, 9:20 PM ET)

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It affects nextcloud security-advisories and 1 other product. Add what you run to find out whether that includes you.

No exploitation reported and no EPSS estimate yet.

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Exploited in the last 30 days

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: 3.3 LOW (v3.1, CNA)CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N
Weakness (CWE): CWE-116
Known exploited: Not in CISA's KEV catalog
EPSS (exploitation in the next 30 days): Not loaded for this CVE
Assigned by: GitHub_M
NVD analysis: Analyzed
Record last updated: Dec 8, 2025
First seen by InfoSec Signals: Oct 9, 2026

Affected products

Affected products

nextcloud security-advisories nextcloud:security_advisories (from the name)	from 1.15.0-beta.1, < 1.15.1; from 1.14.0-beta.1, < 1.14.4; before 1.12.7	CNA record
nextcloud deck nextcloud:deck	before 1.12.7; from 1.14.0 before 1.14.4; from 1.15.0 before 1.15.1	NVD

References

References

https://github.com/nextcloud/security-advisories/security/advisories/GHSA-xjvq-xvr7-xpg6	x-refsource-confirm, patch, vendor-advisory
https://github.com/nextcloud/deck/pull/6671	x-refsource-misc, issue-tracking
https://github.com/nextcloud/deck/commit/afa95d3c507465b9d31af7c88c69b76711ef185a	x-refsource-misc, patch
https://hackerone.com/reports/2326618	x-refsource-misc, permissions-required, vendor-advisory

The CVE record on cve.org NVD's entry

The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.