What’s Vulnerable › Vulnerabilities

CVE-2023-25159: Nextcloud Server previews are accessible without a watermark

• Severity: medium (CVSS 5.3 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.5% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2023-02-13 · updated 2026-06-17
• Weakness: CWE-284

Description

Nextcloud Server is the file server software for Nextcloud, a self-hosted productivity platform, and Nextcloud Office is a document collaboration app for the same platform. Nextcloud Server 24.0.x prior to 24.0.8 and 25.0.x prior to 25.0.1, Nextcloud Enterprise Server 24.0.x prior to 24.0.8 and 25.0.x prior to 25.0.1, and Nextcloud Office (Richdocuments) App 6.x prior to 6.3.1 and 7.x prior to 7.0.1 have previews accessible without a watermark. The download should be hidden and the watermark should get applied. This issue is fixed in Nextcloud Server 25.0.1 and 24.0.8, Nextcloud Enterprise Server 25.0.1 and 24.0.8, and Nextcloud Office (Richdocuments) App 7.0.1 (for 25) and 6.3.1 (for 24). No known workarounds are available.

Affected products

• Nextcloud Server: from 24.0.4 through 24.0.8; 24.0.2, 25.0.0
• nextcloud Richdocuments: from 6.0.0 before 6.3.1; 7.0.0 — fixed in 6.3.1

How to fix

Upgrade to a fixed version: nextcloud Richdocuments 6.3.1. Check the vendor advisory for mitigations.

References

• https://github.com/nextcloud/richdocuments/pull/2579
• https://github.com/nextcloud/security-advisories/security/advisories/GHSA-92g2-h5jv-jjmg
• https://github.com/nextcloud/server/pull/34799
• https://hackerone.com/reports/1745755
• https://github.com/nextcloud/richdocuments/pull/2579
• https://github.com/nextcloud/security-advisories/security/advisories/GHSA-92g2-h5jv-jjmg
• https://github.com/nextcloud/server/pull/34799
• https://hackerone.com/reports/1745755

Get alerted when CVE-2023-25159 or the next vulnerability affects your stack