How severe is CVE-2024-21630?

CVE-2024-21630 has a CVSS 3.x base score of 4.3, rated medium severity. It is exploitable over network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is low, integrity none, and availability none.

Is CVE-2024-21630 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (29th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2024-21630?

CVE-2024-21630 affects Zulip Zulip Server. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2024-21630?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

Does CVE-2024-21630 have an EU (EUVD) identifier?

Yes. CVE-2024-21630 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2024-19272.

When was CVE-2024-21630 published?

CVE-2024-21630 was published on 2024-01-25 and last updated on 2026-06-17.

CVE-2024-21630

CVE-2024-21630 is a medium-severity vulnerability in Zulip Zulip Server with a CVSS 3.x base score of 4.3. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-862.

Key facts

Severity: Medium (CVSS 3.x base score 4.3)
EPSS exploit prediction: 0% (29th percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2024-19272
Weakness: CWE-862
Affected product: Zulip Zulip Server
Published: 2024-01-25
Last modified: 2026-06-17

Description

Zulip is an open-source team collaboration tool. A vulnerability in version 8.0 is similar to CVE-2023-32677, but applies to multi-use invitations, not single-use invitation links as in the prior CVE. Specifically, it applies when the installation has configured non-admins to be able to invite users and create multi-use invitations, and has also configured only admins to be able to invite users to streams. As in CVE-2023-32677, this does not let users invite new users to arbitrary streams, only to streams that the inviter can already see. Version 8.1 fixes this issue. As a workaround, administrators can limit sending of invitations down to users who also have the permission to add users to streams.

Frequently asked questions

What is CVE-2024-21630?: Zulip is an open-source team collaboration tool. A vulnerability in version 8.0 is similar to CVE-2023-32677, but applies to multi-use invitations, not single-use invitation links as in the prior CVE. Specifically, it applies when the installation has configured non-admins to be able to invite users and create multi-use invitations, and has also configured only admins to be able to invite users to streams. As in CVE-2023-32677, this does not let users invite new users to arbitrary streams, only to streams that the inviter can already see. Version 8.1 fixes this issue. As a workaround, administrators can limit sending of invitations down to users who also have the permission to add users to streams.
How severe is CVE-2024-21630?: CVE-2024-21630 has a CVSS 3.x base score of 4.3, rated medium severity. It is exploitable over network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is low, integrity none, and availability none.
Is CVE-2024-21630 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (29th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2024-21630?: CVE-2024-21630 affects Zulip Zulip Server. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2024-21630?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
Does CVE-2024-21630 have an EU (EUVD) identifier?: Yes. CVE-2024-21630 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2024-19272.
When was CVE-2024-21630 published?: CVE-2024-21630 was published on 2024-01-25 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:zulip:zulip_server:*:*:*:*:*:*:*:*

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