CVE-2026-128970

Missing membership acceptance check permits group share-right deletion by invitees in Psono Server

Published Nov 13, 2026 CVSS 3.1 · 5.4 Medium EPSS n/a KEV · Not listed
Description
Psono Server Community Edition versions 1.12.6 through 7.5.0 and Psono Server Enterprise Edition before 7.5.1 do not require accepted group membership when authorizing deletion of group share-rights. The DELETE /share/right/ endpoint checks for a membership matching the target group, the authenticated user, and share_admin=True, but omits accepted=True. An authenticated remote attacker who has been invited to a group with share-admin privileges, and who knows a group share-right UUID, can therefore delete that group's share-right record without accepting the invitation or after declining it. Pending invitations have accepted=None, while declined invitations retain accepted=False and the share_admin flag. Deletion revokes the group's access to the affected share and its contained secrets for all accepted group members, without deleting the underlying data or disclosing secret contents. The issue was fixed in version 7.5.1 of both editions, released on 2026-10-13.

Remediation

Vendor Solution

Upgrade Psono Server Community Edition and Psono Server Enterprise Edition to version 7.5.1 or later. Version 7.5.1 was released for both editions on 2026-10-13. The patch adds accepted=True to the User_Group_Membership authorization query in DeleteShareRightSerializer.validate, making group share-right deletion require both accepted membership and share_admin=True, matching the group authorization check in the create path.


Vendor Workaround

Until the patch is deployed, use authorized group administration to remove pending and declined group memberships carrying share-admin privileges, or clear their share_admin flag. Avoid granting share-admin privileges to unaccepted invitees on affected versions.

Tracking

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Advisories

No advisories available
History
Type Values Removed Values Added
Description Psono Server Community Edition versions 1.12.6 through 7.5.0 and Psono Server Enterprise Edition before 7.5.1 do not require accepted group membership when authorizing deletion of group share-rights. The DELETE /share/right/ endpoint checks for a membership matching the target group, the authenticated user, and share_admin=True, but omits accepted=True. An authenticated remote attacker who has been invited to a group with share-admin privileges, and who knows a group share-right UUID, can therefore delete that group's share-right record without accepting the invitation or after declining it. Pending invitations have accepted=None, while declined invitations retain accepted=False and the share_admin flag. Deletion revokes the group's access to the affected share and its contained secrets for all accepted group members, without deleting the underlying data or disclosing secret contents. The issue was fixed in version 7.5.1 of both editions, released on 2026-10-13.
Title Missing membership acceptance check permits group share-right deletion by invitees in Psono Server
Weaknesses CWE-863
References
Metrics cvssV3_1

{'score': 5.4, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:L'}

Subscriptions

No data.

Weaknesses

Sources

Status
PUBLISHED
Assigner
esaqa
Published
Updated
Nov 13, 2026, 2:25 PM
Reserved
Nov 13, 2026, 1:45 PM
Status
Received
Published
Nov 13, 2026, 3:17 PM
Modified
Nov 13, 2026, 3:17 PM