CVE-2025-47794: Nextcloud Server vulnerable to insecure temporary file creation, race with write access and permission

Severity: medium (CVSS 4.3 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: 2025-05-16 · updated 2026-06-17
Weakness: CWE-284

Description

Nextcloud Server is a self hosted personal cloud system. In Nextcloud Server prior to 29.0.13, 30.0.7, and 31.0.1 and Nextcloud Enterprise Server prior to 26.0.13.13, 27.1.11.13, 28.0.14.4, 29.0.13, 30.0.7, and 31.0.1, an attacker on a multi-user system may read temporary files from Nextcloud running with a different user account, or run a symlink attack. Nextcloud Server versions 29.0.13, 30.0.7, and 31.0.1 and Nextcloud Enterprise Server 26.0.13.13, 27.1.11.13, 28.0.14.4, 29.0.13, 30.0.7, and 31.0.1 fix the issue. No known workarounds are available.

Affected products

Nextcloud Server: from 26.0.0 before 26.0.13.13; from 27.0.0 before 27.1.11.13; from 28.0.0 before 28.0.14.4; from 29.0.0 before 29.0.13; from 30.0.0 before 30.0.7; from 31.0.0 before 31.0.1 — fixed in 26.0.13.13, 27.1.11.13, 28.0.14.4, 29.0.13, 30.0.7, 31.0.1

How to fix

Upgrade to a fixed version: Nextcloud Server 26.0.13.13, 27.1.11.13, 28.0.14.4, 29.0.13. Check the vendor advisory for mitigations.

References

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