Bug 2562256 (CVE-2026-82983)

Summary: CVE-2026-82983 tables: Nextcloud Tables: Information disclosure via missing permission check on share-listing endpoint
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security DevOps Team <prodsec-dev>
Status: NEW --- QA Contact:
Severity: medium Docs Contact:
Priority: medium    
Version: unspecifiedCC: eglynn, jjoyce, jpretori, jschluet, lhh, mburns, mgarciac
Target Milestone: ---Keywords: Security
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Hardware: All   
OS: Linux   
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A flaw was found in Nextcloud Tables. The application fails to properly verify that a requesting user has management permissions before returning table share details. An authenticated user with read-only access can exploit this flaw by directly querying the share-listing endpoint, leading to unauthorized information disclosure of all share recipients and their assigned permission levels.
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oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
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Description OSIDB Bzimport 2026-10-27 18:22:58 UTC
The Tables app's share-listing endpoint (GET /apps/tables/share/table/{tableId}) did not verify that the requesting user has manage-level permission on the table before returning the full list of share recipients (users, groups, and teams) along with their permission levels. A user who was only granted read-data access to a table, and who is correctly prevented from seeing this information in the web UI, could call the endpoint directly to enumerate everyone the table is shared with and their access levels.

This does not expose the table's data itself beyond what the read-data grant already permits, only the list of share recipients and their permission levels.