Auth bypass in Nextcloud Server

CVE-2025-47790

Nextcloud Server is a self hosted personal cloud system. Nextcloud Server prior to 29.0.15, 30.0.9, and 31.0.3 and Nextcloud Enterprise Server prior to 26.0.13.15, 27.1.11.15, 28.0.14.6, 29.0.15, 30.0.9, and 31.0.3 have a bug with session handling. The bug caused skipping the second factor confirmation after a successful login with the username and password when the server was configured with `remember_login_cookie_lifetime` set to `0`, once the session expired on the page to select the second factor and the page is reloaded. Nextcloud Server 29.0.15, 30.0.9, and 31.0.3 and Nextcloud Enterprise Server is upgraded to 26.0.13.15, 27.1.11.15, 28.0.14.6, 29.0.15, 30.0.9 and 31.0.3 contain a patch. As a workaround, set the `remember_login_cookie_lifetime` in config.php to a value other than `0`, e.g. `900`. Beware that this is only a workaround for new sessions created after the configuration change. System administration can delete affected sessions.

Vulnerability class: Broken Authentication

EPSS: 0.003 (24.9th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 6.4 (Medium). Vector: CVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:U/C:H/I:H/A:N.

Affected products

Weakness classification (CWE)

Public proof-of-concept exploits

References

Frequently asked questions

What is CVE-2025-47790?
CVE-2025-47790 is a medium-severity vulnerability in Nextcloud Server, classified under Improper Authentication. CVSS score: 6.4/10. Published 2025-05-16.
How severe is CVE-2025-47790?
Medium severity. CVSS v3 base score is 6.4 out of 10.
Is CVE-2025-47790 known to be exploited?
1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.