CVE-2025-66548Nextcloud Deck app allows to spoof file extensions by using RTLO characters
- 3.3LowCVSS base score
- 0.17%Exploitation in 30 daysEPSS · top 94% of all CVEs
- NoKnown exploitednot in CISA's KEV catalog
- NonePublic exploitsnone known yet
Description
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.
Timeline
ID reserved
By GitHub_M
- 1 day later
· 1 day later
Published
- 3 days later
· 3 days later
Record updated
Changes after publication (a new score, a public exploit, EPSS crossing 1, 10 or 50 %, leaving KEV) are kept since November 2026; earlier ones are not known.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| GitHub_MCNA (assigner) | 3.1 | Low3.3 | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N |
| NVDNVD · Analyzed | 3.1 | Medium5.5 | CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N |
- EPSS (exploitation in 30 days)
- 0.17% · top 94% of all CVEs (15 Nov 2026)
- CISA SSVC
- Exploitation: none · Automatable: no · Technical impact: partial
The list uses the assigner's score when there is one, then CISA's, then NVD's: Low 3.3.
Affected products
nextcloud · security-advisories
- affected >= 1.15.0-beta.1, < 1.15.1
- affected >= 1.14.0-beta.1, < 1.14.4
- affected < 1.12.7
References
References4
- https://github.com/nextcloud/security-advisories/security/advisories/GHSA-xjvq-xvr7-xpg6 (opens in a new tab)x_refsource_CONFIRM
- https://github.com/nextcloud/deck/pull/6671 (opens in a new tab)x_refsource_MISC
- https://github.com/nextcloud/deck/commit/afa95d3c507465b9d31af7c88c69b76711ef185a (opens in a new tab)x_refsource_MISC
- https://hackerone.com/reports/2326618 (opens in a new tab)x_refsource_MISC
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- EUVD EUVD-2025-201466 (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisories (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://cveledger.app/cve/CVE-2025-66548)Record last updated .