Vulnerability · Published Jun 1, 2026 · Assigned by GitHub_M
CVE-2026-45691Nextcloud: Bypass of second factor authentication on DAV endpoints
Medium 5.9
In plain English
A medium-severity improper authentication in security-advisories from nextcloud. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.3% (higher than 22% of all known vulnerabilities).
Official description
Nextcloud is an open source content collaboration platform. In Nextcloud Server from versions 32.0.0 to before 32.0.9, and 33.0.0 to before 33.0.3, a pre-2FA session cookie (created after successful password authentication but before TOTP completion) could be reused as a Bearer token to authenticate against DAV endpoints, granting read/write access and bypassing mandatory two-factor authentication. It is recommended that the Nextcloud Server is upgraded to 33.0.3 or 32.0.9. It is recommended that the Nextcloud Enterprise Server is upgraded to 33.0.3, 32.0.9, 31.0.14.5, 30.0.17.9 or 29.0.16.16
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| nextcloud | security-advisories | >= 32.0.0, < 32.0.9>= 33.0.0, < 33.0.3 |
Weakness: CWE-287 · Vector: CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:L/I:H/A:N
References
- https://github.com/nextcloud/security-advisories/security/advisories/GHSA-mp6x-g55j-w9jw x_refsource_CONFIRM
- https://github.com/nextcloud/server/pull/59758 x_refsource_MISC
- https://hackerone.com/reports/3573399 x_refsource_MISC