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TI-2021-15506 Aliases CVE-2021-37631

Circle can be accessed by non-Circle members in Nextcloud Deck

Priority LOW 31CWE-639Published · Updated

Key facts

Attack vector
Network
Privileges required
Low
User interaction
None
Attack complexity
Low
Impact type
Security bypass
Confidentiality · integrity · availability
High · None · None
Fix status
Fixed

Attack profile from CVSS 3.1 · CNA. Fix status from CNA. Impact type from CWE-639.

Summary

Deck is an open source kanban style organization tool aimed at personal planning and project organization for teams integrated with Nextcloud. In affected versions the Deck application didn't properly check membership of users in a Circle. This allowed other users in the instance to gain access to boards that have been shared with a Circle, even if the user was not a member of the circle. It is recommended that Nextcloud Deck is upgraded to 1.5.1, 1.4.4 or 1.2.9. If you are unable to update it is advised to disable the Deck plugin.

Why it matters now

EPSS 0.01277 70th percentileScored 2026-11-07
Fix Fixed security-advisories (nextcloud): 1.2.9, 1.4.4, 1.5.1

SSVC decision points

Not available: CISA has not published SSVC decision points for this record.

Affected products

VendorProductAffected versionsFixed inStatusSource
nextcloudsecurity-advisoriesbefore 1.2.9; 1.3.0 to before 1.4.4; 1.5.0 to before 1.5.11.2.9, 1.4.4, 1.5.1Patch availableCNA
  • security-advisories Vendornextcloud Affected before 1.2.9; 1.3.0 to before 1.4.4; 1.5.0 to before 1.5.1 Fixed in 1.2.9, 1.4.4, 1.5.1 Patch available CNA

CPE configurations NVD · 1

CPEVersionsRoleVendor
cpe:2.3:a:nextcloud:deck:*:*:*:*:*:*:*:*before 1.2.9; 1.3.0 to before 1.4.4; 1.5.0 to before 1.5.1Vulnerablenextcloud
  • cpe:2.3:a:nextcloud:deck:*:*:*:*:*:*:*:* Versions before 1.2.9; 1.3.0 to before 1.4.4; 1.5.0 to before 1.5.1 Vulnerable ·nextcloud

Remediation

  • Fix · CNA security-advisories (nextcloud) Fixed in 1.2.9, 1.4.4, 1.5.1

Timeline

  1. 2026-10-02 Threatist record created from CVE-2021-37631

References

Patch 1

Advisory 3

  • TI-2023-08718 Nextcloud Deck card vulnerable to data leak to unauthorized users via reference preview cache CVSS 3.1MEDIUM 5.8
  • TI-2022-11703 Possibility for anyone to add a stack with existing tasks on anyone's board in Nextcloud Deck CVSS 3.1MEDIUM 5.0
  • TI-2022-08716 Error in deleting deck cards attachment reveals the full application path in Nextcloud Deck CVSS 3.1MEDIUM 4.3
  • TI-2021-16610 Missing permission check on Deck API CVSS 3.1HIGH 8.1
  • TI-2020-06600 Improper access control in Nextcloud Deck CVSS 3.1HIGH 8.0
  • TI-2021-05774 Information disclosure in Nextcloud Deck CVSS 3.1MEDIUM 6.5
See all 16 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences