CVE-2026-45264

Nextcloud: ACL Rename Permission Bypass in Team Folders Allows Unauthorized File Renames

State: Published
Severity: 4.3 Medium
Published: Jun 1, 2026
Updated: Jun 1, 2026
Reserved: May 11, 2026

Description

Nextcloud is an open source content collaboration platform. From versions 17.0.0 to before 17.0.15, 18.0.0 to before 18.1.12, 19.0.0 to before 19.1.16, 20.0.0 to before 20.1.11, and 21.0.0 to before 21.0.4, a user with READ and CREATE permission, but no UPDATE permission for a team folder can rename files in the team folder. This issue has been patched in versions 17.0.15, 18.1.12, 19.1.16, 20.1.11, and 21.0.4.

Scores

CVSS	Score	Vector	Source
3.1	4.3 Medium	CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N	GitHub_M

Weaknesses

CWE-284 Improper Access Control

Affected Products

Product	Versions
security-advisoriesnextcloud	>= 17.0.0, < 17.0.15Affected >= 18.0.0, < 18.1.12Affected >= 19.0.0, < 19.1.16Affected >= 20.0.0, < 20.1.11Affected >= 21.0.0, < 21.0.4Affected

References

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