# CVE-2026-128970: Missing membership acceptance check permits group share-right deletion by invitees in Psono Server Status: published. Published: 2026-11-13. Updated: 2026-11-13. 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 - fix: 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. (source: CNA: esaqa) - 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. (source: CNA: esaqa) - fix: The reporting source identifies this reference as a patch. Check the advisory for affected versions and supported release branches. (source: CNA: esaqa) — https://gitlab.com/esaqa/psono/psono-server/-/commit/86e7ce7fdbb04fc4ae3430cc434179630948d48d ## Affected products and versions - esaqa GmbH / Psono: ≥ 1.12.6; < 7.5.1 (affected, semver). Source: CNA: esaqa - esaqa GmbH / Psono: ≥ 0; < 7.5.1 (affected, semver). Source: CNA: esaqa ## Severity and prioritization - CVSS 3.1: 5.4 (medium); CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:L; source: CNA: esaqa - CVSS 3.1: 5.4 (medium); CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:L; source: NVD: fdf66990-8419-4c8c-8848-ec15d75773b4 - CISA KEV: No listing in collected sources - EPSS: Not available - SSVC: exploitation none; automatable no; technical impact partial; source ADP: CISA-ADP - Weaknesses: CWE-863 ## Exploit evidence No exploit evidence in collected sources. This is not proof of no exploitation. ## References - https://gitlab.com/esaqa/psono/psono-server/-/commit/86e7ce7fdbb04fc4ae3430cc434179630948d48d (CNA: esaqa; patch) - https://gitlab.com/esaqa/psono/psono-server/-/releases/v7.5.1 (CNA: esaqa; release-notes) - https://gitlab.com/esaqa/esaqa/security-advisories/-/blob/master/advisories/CVE-2026-128970.md (CNA: esaqa; vendor-advisory) - https://gitlab.com/esaqa/psono/psono-server/-/blob/v7.5.0/psono/restapi/serializers/delete_share_right.py (CNA: esaqa; technical-description) - https://gitlab.com/esaqa/psono/psono-server/-/blob/v7.5.0/psono/restapi/serializers/create_share_right.py (CNA: esaqa; technical-description) - https://gitlab.com/esaqa/psono/psono-server/-/blob/v7.5.0/psono/restapi/views/membership_decline.py (CNA: esaqa; technical-description) - https://gitlab.com/esaqa/psono/psono-server/-/commit/11f9aa69dae370cd4f0213f4d03d1b1cc4df36dd (CNA: esaqa; technical-description) - https://gitlab.com/esaqa/psono/psono-server (CNA: esaqa; product) - https://gitlab.com/esaqa/esaqa/security-advisories/-/blob/master/advisories/CVE-2026-128970.md (fdf66990-8419-4c8c-8848-ec15d75773b4) - https://gitlab.com/esaqa/psono/psono-server (fdf66990-8419-4c8c-8848-ec15d75773b4) - https://gitlab.com/esaqa/psono/psono-server/-/blob/v7.5.0/psono/restapi/serializers/create_share_right.py (fdf66990-8419-4c8c-8848-ec15d75773b4) - https://gitlab.com/esaqa/psono/psono-server/-/blob/v7.5.0/psono/restapi/serializers/delete_share_right.py (fdf66990-8419-4c8c-8848-ec15d75773b4) - https://gitlab.com/esaqa/psono/psono-server/-/blob/v7.5.0/psono/restapi/views/membership_decline.py (fdf66990-8419-4c8c-8848-ec15d75773b4) - https://gitlab.com/esaqa/psono/psono-server/-/commit/11f9aa69dae370cd4f0213f4d03d1b1cc4df36dd (fdf66990-8419-4c8c-8848-ec15d75773b4) - https://gitlab.com/esaqa/psono/psono-server/-/commit/86e7ce7fdbb04fc4ae3430cc434179630948d48d (fdf66990-8419-4c8c-8848-ec15d75773b4) - https://gitlab.com/esaqa/psono/psono-server/-/releases/v7.5.1 (fdf66990-8419-4c8c-8848-ec15d75773b4) ## Provenance - CNA: esaqa: https://www.cve.org/CVERecord?id=CVE-2026-128970; retrieved 2026-11-13; source updated 2026-11-13 - NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-128970; retrieved 2026-11-13; source updated 2026-11-13 Revision: 878d91c5aa0437852f2473e2e71a07cb6356ef6630299b898c56c9a67b8563f0 Canonical: https://y2.dev/cve/CVE-2026-128970 ## Agent and API access Public CVE pages, Markdown, and JSON are free to read without an account or API key. - Public catalog: https://y2.dev/cve/index.json. 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