Nextcloud v<=5.2.6: Missing perm. check allows cross-user form read
CVE-2026-45267 Published on June 1, 2026

Nextcloud: Missing permission check for from submissions
Nextcloud is an open source content collaboration platform. Prior to version 5.2.6, a missing permissions check allowed users to request reading form submissions of other users. This issue has been patched in version 5.2.6.

NVD

Vulnerability Analysis

CVE-2026-45267 can be exploited with network access, and requires small amount of user privileges. This vulnerability is considered to have a low attack complexity. The potential impact of an exploit of this vulnerability is considered to have a high impact on confidentiality, with no impact on integrity and availability.

Attack Vector:
NETWORK
Attack Complexity:
LOW
Privileges Required:
LOW
User Interaction:
NONE
Scope:
UNCHANGED
Confidentiality Impact:
HIGH
Integrity Impact:
NONE
Availability Impact:
NONE

Weakness Types

What is an Information Disclosure Vulnerability?

The product exposes sensitive information to an actor that is not explicitly authorized to have access to that information.

CVE-2026-45267 has been classified to as an Information Disclosure vulnerability or weakness.

What is an AuthZ Vulnerability?

The software does not perform an authorization check when an actor attempts to access a resource or perform an action.

CVE-2026-45267 has been classified to as an AuthZ vulnerability or weakness.


Affected Versions

nextcloud security-advisories Version < 5.2.6 is affected by CVE-2026-45267