Description
Abusing the federated share endpoint, an attacker can write arbitrary rows into the oc_share_external database table. These rows persist indefinitely — there is no automatic cleanup mechanism. Three distinct denial-of-service conditions follow from this write primitive, all triggered from the same unauthenticated source and all self-renewing on a 24-hour cycle for as long as the injected rows remain in the database.
Published: 2026-10-27
Score: 7.5 High
EPSS: n/a
KEV: No
Impact: n/a
Action: n/a
AI Analysis

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Remediation

No vendor fix or workaround currently provided.

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Tracking

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Advisories

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References
History

Tue, 27 Oct 2026 19:15:00 +0000

Type Values Removed Values Added
First Time appeared Nextcloud
Nextcloud server
Vendors & Products Nextcloud
Nextcloud server

Tue, 27 Oct 2026 18:00:00 +0000

Type Values Removed Values Added
Title Denial of Service via Unauthenticated Write to oc_share_external Table

Tue, 27 Oct 2026 16:30:00 +0000

Type Values Removed Values Added
Description Abusing the federated share endpoint, an attacker can write arbitrary rows into the oc_share_external database table. These rows persist indefinitely — there is no automatic cleanup mechanism. Three distinct denial-of-service conditions follow from this write primitive, all triggered from the same unauthenticated source and all self-renewing on a 24-hour cycle for as long as the injected rows remain in the database.
Weaknesses CWE-400
References
Metrics cvssV3_0

{'score': 7.5, 'vector': 'CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H'}


Subscriptions

Nextcloud Server
cve-icon MITRE

Status: PUBLISHED

Assigner: hackerone

Published:

Updated: 2026-10-27T16:15:34.778Z

Reserved: 2026-08-20T15:00:00.606Z

Link: CVE-2026-77167

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Received

Published: 2026-10-27T17:17:02.673

Modified: 2026-10-27T17:17:02.673

Link: CVE-2026-77167

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2026-10-27T19:00:08Z

Weaknesses