How severe is CVE-2024-56136?

CVE-2024-56136 has a CVSS 3.x base score of 5.3, rated medium severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is low, integrity none, and availability none.

Is CVE-2024-56136 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (42nd percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2024-56136?

CVE-2024-56136 affects Zulip Zulip Server. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2024-56136?

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

Does CVE-2024-56136 have an EU (EUVD) identifier?

Yes. CVE-2024-56136 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2024-52989.

When was CVE-2024-56136 published?

CVE-2024-56136 was published on 2025-01-16 and last updated on 2026-06-17.

CVE-2024-56136

CVE-2024-56136 is a medium-severity vulnerability in Zulip Zulip Server with a CVSS 3.x base score of 5.3. 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-200.

Key facts

Severity: Medium (CVSS 3.x base score 5.3)
CVSS v4: 6.9
EPSS exploit prediction: 1% (42nd percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2024-52989
Weakness: CWE-200
Affected product: Zulip Zulip Server
Published: 2025-01-16
Last modified: 2026-06-17

Description

Zulip server provides an open-source team chat that helps teams stay productive and focused. Zulip Server 7.0 and above are vulnerable to an information disclose attack, where, if a Zulip server is hosting multiple organizations, an unauthenticated user can make a request and determine if an email address is in use by a user. Zulip Server 9.4 resolves the issue, as does the `main` branch of Zulip Server. Users are advised to upgrade. There are no known workarounds for this issue.

Frequently asked questions

What is CVE-2024-56136?: Zulip server provides an open-source team chat that helps teams stay productive and focused. Zulip Server 7.0 and above are vulnerable to an information disclose attack, where, if a Zulip server is hosting multiple organizations, an unauthenticated user can make a request and determine if an email address is in use by a user. Zulip Server 9.4 resolves the issue, as does the `main` branch of Zulip Server. Users are advised to upgrade. There are no known workarounds for this issue.
How severe is CVE-2024-56136?: CVE-2024-56136 has a CVSS 3.x base score of 5.3, rated medium severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is low, integrity none, and availability none.
Is CVE-2024-56136 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (42nd percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2024-56136?: CVE-2024-56136 affects Zulip Zulip Server. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2024-56136?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
Does CVE-2024-56136 have an EU (EUVD) identifier?: Yes. CVE-2024-56136 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2024-52989.
When was CVE-2024-56136 published?: CVE-2024-56136 was published on 2025-01-16 and last updated on 2026-06-17.

References

Affected products (1)

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

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