What’s Vulnerable › Vulnerabilities

CVE-2026-25742: Zulip: Anonymous File Access After Disabling Spectator Access

• Severity: medium (CVSS 5.3 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.3% probability of exploitation in the next 30 days
• Public exploit or detection template: yes
• Published: 2026-04-03 · updated 2026-07-24
• Weakness: CWE-862

Description

Zulip is an open-source team collaboration tool. Prior to version 11.6, Zulip is an open-source team collaboration tool. From version 1.4.0 to before version 11.6, even after spectator access (enable_spectator_access / WEB_PUBLIC_STREAMS_ENABLED) is disabled, attachments originating from web-public streams can still be retrieved anonymously. As a result, file contents remain accessible even after public access is intended to be disabled. Similarly, even after spectator access is disabled, the /users/me/<stream_id>/topics endpoint remains reachable anonymously, allowing retrieval of topic history for web-public streams. This issue has been patched in version 11.6. This issue has been patched in version 11.6.

Affected products

• zulip: from 1.4.0 before 11.6 — fixed in 11.6

How to fix

Upgrade to a fixed version: zulip 11.6. Check the vendor advisory for mitigations.

References

• https://github.com/zulip/zulip/commit/3c045414299680b9f5dca7d76cf6cef6121c0236
• https://github.com/zulip/zulip/commit/41e23347b5218b3b0397a55176c7d97396735bae
• https://github.com/zulip/zulip/releases/tag/11.6
• https://github.com/zulip/zulip/security/advisories/GHSA-f47p-xjqq-g28w
• https://github.com/zulip/zulip/security/advisories/GHSA-f47p-xjqq-g28w

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