5.3
MEDIUM CVSS 3.1
CVE-2026-25742
Zulip: Anonymous File Access After Disabling Spectator Access
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.

INFO

Published Date :

April 3, 2026, 9:17 p.m.

Last Modified :

April 3, 2026, 9:17 p.m.

Remotely Exploit :

Yes !
Affected Products

The following products are affected by CVE-2026-25742 vulnerability. Even if cvefeed.io is aware of the exact versions of the products that are affected, the information is not represented in the table below.

No affected product recoded yet

CVSS Scores
The Common Vulnerability Scoring System is a standardized framework for assessing the severity of vulnerabilities in software and systems. We collect and displays CVSS scores from various sources for each CVE.
Score Version Severity Vector Exploitability Score Impact Score Source
CVSS 3.1 MEDIUM [email protected]
Solution
Update Zulip to version 11.6 or later to fix anonymous access to attachments and topic history.
  • Update Zulip to version 11.6 or later.
  • Verify spectator access settings.
  • Remove any residual public stream configurations.
References to Advisories, Solutions, and Tools
CWE - Common Weakness Enumeration

While CVE identifies specific instances of vulnerabilities, CWE categorizes the common flaws or weaknesses that can lead to vulnerabilities. CVE-2026-25742 is associated with the following CWEs:

Common Attack Pattern Enumeration and Classification (CAPEC)

Common Attack Pattern Enumeration and Classification (CAPEC) stores attack patterns, which are descriptions of the common attributes and approaches employed by adversaries to exploit the CVE-2026-25742 weaknesses.

We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).

Results are limited to the first 15 repositories due to potential performance issues.

The following list is the news that have been mention CVE-2026-25742 vulnerability anywhere in the article.

The following table lists the changes that have been made to the CVE-2026-25742 vulnerability over time.

Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.

  • New CVE Received by [email protected]

    Apr. 03, 2026

    Action Type Old Value New Value
    Added 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.
    Added CVSS V3.1 AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N
    Added CWE CWE-862
    Added Reference https://github.com/zulip/zulip/commit/3c045414299680b9f5dca7d76cf6cef6121c0236
    Added Reference https://github.com/zulip/zulip/commit/41e23347b5218b3b0397a55176c7d97396735bae
    Added Reference https://github.com/zulip/zulip/releases/tag/11.6
    Added Reference https://github.com/zulip/zulip/security/advisories/GHSA-f47p-xjqq-g28w
EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days. Following chart shows the EPSS score history of the vulnerability.