SCA: security update for nextcloud-mcp-server (GHSA-8vh3-g2qg-2h2c)

critical Tenable Self-Hosted Container Security Plugin ID 446273

Description

There are packages installed that are affected by a vulnerability referenced in the following CVE:

- Nextcloud MCP Server is a production-ready MCP server that connects AI assistants to a Nextcloud instance.
Prior to 0.117.2, the POST /webhooks/nextcloud endpoint in nextcloud_mcp_server/vector/webhook_receiver.py
has no authentication by default because WEBHOOK_SECRET defaults to None and startup validation does not
require it. When WEBHOOK_SECRET is unset, handle_nextcloud_webhook() accepts unauthenticated requests. The
payload["user"]["uid"] field parsed in nextcloud_mcp_server/vector/webhook_parser.py is attacker-
controlled and is used without an authenticated-session cross-check for Qdrant operations, allowing a
network attacker to delete or trigger re-indexing of vector embeddings for any user and to destroy the
semantic search index by sending forged deletion events. This issue is fixed in version 0.117.2.
(CVE-2026-55640)

Solution

Update the nextcloud-mcp-server library and its related packages to version 0.117.2 or later.

Plugin Details

Severity: Critical

ID: 446273

Version: Revision 1.1

Type: Local

Family: SCA Checks

Published: 8/25/2026

Updated: 8/25/2026

Risk Information

VPR

Risk Factor: Medium

Score: 4.3

Percentile: 53.5

Vendor

Vendor Severity: Critical

CVSS v2

Risk Factor: High

Base Score: 9.4

Temporal Score: 7

Vector: CVSS2#AV:N/AC:L/Au:N/C:N/I:C/A:C

CVSS Score Source: CVE-2026-55640

CVSS v3

Risk Factor: Critical

Base Score: 9.1

Temporal Score: 7.9

Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:H

Temporal Vector: CVSS:3.0/E:U/RL:O/RC:C

Vulnerability Information

Exploit Ease: No known exploits are available

Patch Publication Date: 8/25/2026

Vulnerability Publication Date: 8/25/2026

Reference Information

CVE: CVE-2026-55640

cwe: CWE-306

Detections

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