---
id: "CVE-2023-49105"
kind: "vulnerability"
aliases: ["CVE-2023-49105"]
title: "owncloud server: An issue was discovered in ownCloud owncloud/core before 10.13.1"
severity: "critical"
cvss: 9.8
epss: null
exploited: true
status: "open"
category: "vendor"
products: [{"name": "ownCloud ownCloud", "fixed": [], "affected": "", "ecosystem": "vendor"}, {"name": "owncloud server", "fixed": ["10.13.1"], "affected": ">= 10.6.0, < 10.13.1", "ecosystem": "vendor"}]
ecosystems: ["vendor"]
tags: ["exploited", "file-sharing", "owncloud", "self-hosted", "vendor"]
not_affected_if: ["managed-hosting", "no-owncloud-deployment"]
published_at: "2023-11-21T22:15:08+00:00"
first_seen_at: "2026-10-23T19:11:51+00:00"
updated_at: "2026-10-23T23:44:52+00:00"
sources: [{"source": "kev", "url": "https://www.cisa.gov/known-exploited-vulnerabilities-catalog?search_api_fulltext=CVE-2023-49105", "first_seen_at": "2026-10-23T19:11:51+00:00"}, {"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2023-49105", "first_seen_at": "2026-10-23T23:44:52+00:00"}]
---

# owncloud server: An issue was discovered in ownCloud owncloud/core before 10.13.1

ownCloud has an authentication bypass where an attacker who knows a victim's username can read, change, or delete that user's files without logging in, if the victim has no signing key configured. CISA lists it as actively exploited.

_Summary, check and fix written by a model from the sources; labelled as such._

## Affected

- vendor:ownCloud ownCloud affected ? fixed ?
- vendor:owncloud server affected >= 10.6.0, < 10.13.1 fixed 10.13.1

## How to check

Check whether the ownCloud app's signing-key is configured for users (look for signing-key settings in your ownCloud admin config) unknown
Confirm your ownCloud version against the vendor advisory: unknown
Review web server logs for unauthenticated requests to file endpoints: unknown

## Fix

Apply the vendor's fixed ownCloud release or mitigation; the sources do not name the fixed version. Configure a signing key for affected users as the interim mitigation, or take the service offline if no mitigation is available.

## Timeline

- 2026-10-23T19:11:51+00:00 kev https://www.cisa.gov/known-exploited-vulnerabilities-catalog?search_api_fulltext=CVE-2023-49105
- 2026-10-23T23:44:52+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2023-49105

## From the sources

ownCloud contains an improper authentication vulnerability that allows an attacker to access, modify, or delete any file without authentication if the username of a victim is known, and the victim has no signing-key configured.

CISA required action: Apply mitigations in accordance with vendor instructions, ensuring compliance with CISA’s BOD 26-04 Prioritizing Security Updates Based on Risk (see URL in Notes) guidance and CISA’s “Forensics Triage Requirements” (see URL in Notes). Follow applicable BOD 26-04 guidance for cloud services or discontinue use of the product if mitigations are unavailable. Stakeholders are responsible for evaluating each asset's internet exposure and ensuring adherence to BOD 26-04 patching guidelines.

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_Free to read at a human pace. An API with keys and an MCP server are in preparation; early access: hello@infrastack.ai_