CVE-2021-37631

Name: CVE-2021-37631
Creator: NVD / NIST
Published: 2021-09-07T20:15:07.923+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

MEDIUMCVSS 6.5/10EPSS 1.24%

Last modified Jun 17, 2026

CVE-2021-37631 is a medium-severity vulnerability rated 6.5/10 on the CVSS scale. 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. EPSS estimates a 1.24% chance of exploitation in the next 30 days.

Description

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.

Metrics

CVSS 3.1

6.5/10

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N

EPSS Probability

1.24%

65.3th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

Affected Software

Vendor	Product	Versions
Nextcloud	Deck	< 1.2.9
Nextcloud	Deck	>= 1.3.0, < 1.4.4
Nextcloud	Deck	>= 1.5.0, < 1.5.1

References

https://github.com/nextcloud/deck/pull/3217Patch, Third Party Advisory
https://github.com/nextcloud/security-advisories/security/advisories/GHSA-4mxp-j277-82hrThird Party Advisory
https://hackerone.com/reports/1256021Permissions Required, Third Party Advisory
https://hackerone.com/reports/1280931Permissions Required, Third Party Advisory
https://github.com/nextcloud/deck/pull/3217Patch, Third Party Advisory
https://github.com/nextcloud/security-advisories/security/advisories/GHSA-4mxp-j277-82hrThird Party Advisory
https://hackerone.com/reports/1256021Permissions Required, Third Party Advisory
https://hackerone.com/reports/1280931Permissions Required, Third Party Advisory

Timeline

Published: Sep 7, 2021
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2021-37631?

How severe is CVE-2021-37631?

CVE-2021-37631 has a CVSS score of 6.5/10 (MEDIUM severity). The EPSS model estimates a 1.24% probability of exploitation in the next 30 days.

How do I fix CVE-2021-37631?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2021-37631?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST