CVE-2026-45691

Published Jun 1, 2026

Last updated a day ago

CVSS medium 5.9

Overview

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
Source
security-advisories@github.com
NVD status
Analyzed
Products
nextcloud_server

Risk scores

CVSS 3.1

Type
Secondary
Base score
5.9
Impact score
4.2
Exploitability score
1.6
Vector string
CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:L/I:H/A:N
Severity
MEDIUM

Weaknesses

security-advisories@github.com
CWE-287

Social media

Hype score
Not currently trending

Configurations

Related CVEs

  1. Nextcloud is an open source content collaboration platform. In Nextcloud Server from versions 31.0.0 to before 31.0.12, and 32.0.0 to before 32.0.3, a missing check of a relation allowed authenticated users with access to any file comment, to read the content of all comments. It is recommended that the Nextcloud Server is upgraded to 31.0.12 or 32.0.3. It is recommended that the Nextcloud Enterprise Server is upgraded to 21.0.9.20, 22.2.10.35, 23.0.12.31, 24.0.12.30, 25.0.13.25, 26.0.13.22, 27.1.11.22, 28.0.14.13, 29.0.16.10, 30.0.17.5, 31.0.12 or 32.0.3•CVE-2026-45810
  2. 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, an authentication bypass vulnerability allowed attackers with knowledge of a user's password to circumvent two-factor authentication (2FA) protections. When a user initiated login with valid credentials on a 2FA-enabled account, the system created a temporary session token before enforcing the second factor challenge. This token could be extracted and replayed via HTTP Basic Authentication to gain unauthorized access to authenticated endpoints. 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•CVE-2026-45690
  3. Nextcloud is an open source content collaboration platform. From versions 32.0.0 to before 32.0.9, and 33.0.0 to before 33.0.3, when a user shares a folder or file with a Nextcloud Team that includes an external member (a person added via email address who does not have a Nextcloud account), the system automatically creates a public link for that external member. This public link is not displayed in the share section of the folder, so the folder owner has no knowledge of its existence. It is sent via email to the external member. It grants the same permissions (read, write, delete, reshare, download) as the Team’s access. An attacker who receives or intercepts this link can access, modify, delete, reshare, and download all data in the shared folder without any further authentication. The folder owner cannot see or revoke the link through the normal sharing interface. This issue has been patched in versions 32.0.9 and 33.0.3.•CVE-2026-45285
  4. Nextcloud is an open source content collaboration platform. In Nextcloud Server from versions 32.0.0 to before 32.0.2, and 33.0.0 to before 33.0.1, the files_lock app did not properly validate the ownership of files when processing DAV lock and unlock requests. An authenticated user could lock or unlock files belonging to other users by targeting their absolute WebDAV paths. Additionally, lock tokens were disclosed to unauthorized callers in error responses, allowing attackers to remove token-based locks placed by other users' client applications. It is recommended that the Nextcloud Server is upgraded to 32.0.2 or 33.0.1. It is recommended that the Nextcloud Enterprise Server is upgraded to 31.0.14.4 or 32.0.2 or 33.0.1•CVE-2026-45283
  5. 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, an authenticated attacker can access attachments of link shares when knowing the share token, circumventing password protection or download restrictions. It is applicable to any file that is shared directly, as the attacker only needs to know a documentId they own, apart of the mentioned share token. For shared folders the attacker has to know or guess a documentId of a file that is included inside the folder, making it much harder to exploit. The attacker can only extract an attachments, but not the file shared file or folder itself. 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, 29.0.16.16, 28.0.14.17 or 27.1.11.5•CVE-2026-45282

References

Sources include official advisories and independent security research.