Security Flaw in Zulip Team Collaboration Tool by Zendesk
CVE-2026-25742

5.3MEDIUM

Key Information:

Vendor

Zulip

Status
Zulip
Vendor
CVE Published:
3 April 2026

What is CVE-2026-25742?

An information exposure vulnerability exists in the Zulip team collaboration tool prior to version 11.6. Even with spectator access disabled, sensitive attachments from web-public streams can still be accessed anonymously. This flaw allows unauthorized users to retrieve file contents and access topic history from public streams, undermining the intended privacy settings. The issue has been resolved in version 11.6.

Affected Version(s)

zulip < 11.6

References

https://github.com/zulip/zulip/security/advisories/GHSA-f...
x_refsource_CONFIRM
https://github.com/zulip/zulip/commit/3c045414299680b9f5d...
x_refsource_MISC
https://github.com/zulip/zulip/commit/41e23347b5218b3b039...
x_refsource_MISC

CVSS V3.1

Score:
5.3
Severity:
MEDIUM
Confidentiality:
Low
Integrity:
None
Availability:
Low
Attack Vector:
Network
Attack Complexity:
Low
Privileges Required:
None
User Interaction:
None
Scope:
Unchanged

Timeline

  • Vulnerability published

  • Vulnerability Reserved

.