CVE-2023-32677: Zulip is an open-source team collaboration tool with unique topic-based threading. Zulip administrators can configure Zulip to limit who can add users...

Description

Zulip is an open-source team collaboration tool with unique topic-based threading. Zulip administrators can configure Zulip to limit who can add users to streams, and separately to limit who can invite users to the organization. In Zulip Server 6.1 and below, the UI which allows a user to invite a new user also allows them to set the streams that the new user is invited to -- even if the inviting user would not have permissions to add an existing user to streams. While such a configuration is likely rare in practice, the behavior does violate security-related controls. This does not let a user invite new users to streams they cannot see, or would not be able to add users to if they had that general permission. This issue has been addressed in version 6.2. Users are advised to upgrade. Users unable to upgrade may limit sending of invitations down to users who also have the permission to add users to streams.

Metrics

CVSS 3.1

3.1/10

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

EPSS Probability

0.56%

42.5th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

Affected Software

Vendor	Product	Versions
Zulip	Zulip	< 6.2

References

https://github.com/zulip/zulip/commit/7c2693a2c64904d1d0af8503b57763943648cbe5Patch, Third Party Advisory
https://github.com/zulip/zulip/security/advisories/GHSA-mrvp-96q6-jpvcThird Party Advisory
https://zulip.com/help/configure-who-can-invite-to-streamsProduct
https://zulip.com/help/restrict-account-creation#change-who-can-send-invitationsProduct
https://github.com/zulip/zulip/commit/7c2693a2c64904d1d0af8503b57763943648cbe5Patch, Third Party Advisory
https://github.com/zulip/zulip/security/advisories/GHSA-mrvp-96q6-jpvcThird Party Advisory
https://zulip.com/help/configure-who-can-invite-to-streamsProduct
https://zulip.com/help/restrict-account-creation#change-who-can-send-invitationsProduct

Timeline

Published: May 19, 2023
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2023-32677?

Zulip is an open-source team collaboration tool with unique topic-based threading. Zulip administrators can configure Zulip to limit who can add users to streams, and separately to limit who can invite users to the organization. In Zulip Server 6.1 and below, the UI which allows a user to invite a new user also allows them to set the streams that the new user is invited to -- even if the inviting user would not have permissions to add an existing user to streams. While such a configuration is likely rare in practice, the behavior does violate security-related controls. This does not let a user invite new users to streams they cannot see, or would not be able to add users to if they had that general permission. This issue has been addressed in version 6.2. Users are advised to upgrade. Users unable to upgrade may limit sending of invitations down to users who also have the permission to add users to streams.

How severe is CVE-2023-32677?

CVE-2023-32677 has a CVSS score of 3.1/10 (LOW severity). The EPSS model estimates a 0.56% probability of exploitation in the next 30 days.

How do I fix CVE-2023-32677?

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.