CVE-2025-66551Network attack vector

Unauthorized column moves via unchecked table identifier

Published Dec 5, 2025 · Updated Dec 9, 2025

Authorization bypass in Nextcloud Tables before 0.8.6 and 0.9.0-beta.1 through 0.9.2 lets remote authenticated users move columns across tables. The legacy ColumnController update path passes an attacker-supplied table identifier to ColumnService, which assigns it to the selected column without confirming ownership of the destination table. A valid account with Tables access is required; exploitation changes another user's table structure and can disrupt its use.

CVSS severity6.3
Medium
EPSS probability0.25%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Authorization bypass in Nextcloud Tables before 0.8.6 and 0.9.0-beta.1 through 0.9.2 lets remote authenticated users move columns across tables. The legacy ColumnController update path passes an attacker-supplied table identifier to ColumnService, which assigns it to the selected column without confirming ownership of the destination table. A valid account with Tables access is required; exploitation changes another user's table structure and can disrupt its use.

The record

CVE
CVE-2025-66551
Published
Dec 5, 2025
Updated
Dec 9, 2025
Vendor
Nextcloud GmbH
Product
Security Advisories
Classifications
CWE-639, T1565.001
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Dec 5, 2025CVE publishedPublication date reported by the CVE source.
  2. Dec 9, 2025Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=< 0.8.6
  2. Affected versionversion=>= 0.9.0-beta.1, < 0.9.3

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

Nextcloud GmbH · Security Advisoriesversion=< 0.8.6; version=>= 0.9.0-beta.1, < 0.9.3

Published CVSS scores

4.3NIST NVDCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N
6.3GitHub, Inc.CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:N/I:H/A:L

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-639Authorization Bypass Through User-Controlled Key
T1565.001Stored Data Manipulation

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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