CVE-2021-30479

5.3 mediumEPSS 0.9%

Medium (5.3) in zulip zulip server. EPSS 0.9% chance of exploitation in the next 30 days.

An issue was discovered in Zulip Server before 3.4. A bug in the implementation of the all_public_streams API feature resulted in guest users being able to receive message traffic to public streams that should have been only accessible to members of the organization.

Severity

CVSS 3.1

5.3 medium

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

EPSS: 0.9% chance of exploitation in the next 30 days; higher than 58% of CVEs (scores of 2026-10-31)
CWE: CWE-269
Published: 2021-04-15
Modified: 2026-06-17
Record from: the NVD, synced 2026-10-19

Affected

zulip:zulip_server

References

https://blog.zulip.com/2021/04/14/zulip-server-3-4/
https://blog.zulip.com/2021/04/14/zulip-server-3-4/

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