What’s Vulnerable › Vulnerabilities

CVE-2024-56136: /api/v1/jwt/fetch_api_key endpoint can leak if an email address has an account in Zulip server

• Severity: medium (CVSS 5.3 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.6% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2025-01-16 · updated 2026-06-17
• Weakness: CWE-200

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.

Affected products

• zulip: from 7.0 before 9.4 — fixed in 9.4

How to fix

Upgrade to a fixed version: zulip 9.4. Check the vendor advisory for mitigations.

References

• https://github.com/zulip/zulip/commit/c6334a765b1e6d71760e4a3b32ae5b8367f2ed4d
• https://github.com/zulip/zulip/security/advisories/GHSA-5xg8-xhfj-4hm6

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