Which versions of Zulip Server are affected by CVE-2025-27149?

CVE-2025-27149 presents moderate security risk rated CVSS 4.6. Exploitation could compromise the security of affected deployments.

How to fix or mitigate CVE-2025-27149?

Within 30 days: Identify affected systems and apply vendor patches as part of regular patch cycle. Monitor vendor channels for patch availability.

Zulip Server CVE-2025-27149

Q: What is the CVSS score of CVE-2025-27149?

CVE-2025-27149 has a CVSS 4.0 base score of 4.6 (Medium). CVSS vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:A/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X. EPSS exploitation probability: 0.2%.

MEDIUM

Exposure of Sensitive System Information to an Unauthorized Control Sphere (CWE-497)

2025-03-31 security-advisories@github.com

Information Disclosure Zulip Server

4.6

CVSS 4.0 · GitHub Advisory

Severity by source

GitHub Advisory PRIMARY

4.6 MEDIUM

CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:A/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

Primary rating from GitHub Advisory · only source for this CVE.

CVSS VectorGitHub Advisory

CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:A/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

Attack Vector

Network

Attack Complexity

Low

Privileges Required

High

User Interaction

Scope

Lifecycle Timeline

Analysis Generated

Mar 28, 2026 - 18:34 vuln.today

CVE Published

Mar 31, 2025 - 16:15 nvd

MEDIUM 4.6

DescriptionGitHub Advisory

Zulip server provides an open-source team chat that helps teams stay productive and focused. Prior to 10.0, the data export to organization administrators feature in Zulip leaks private data. The collection of user-agent types identifying specific integrations or HTTP libraries (E.g., ZulipGitlabWebhook, okhttp, or PycURL) that have been used to access any organization on the server was incorrectly included in all three export types, regardless of if they were used to access the exported organization or not. The "public data" and "with consent" exports metadata including the titles of some topics in private channels which the administrator otherwise did not have access to, and none of the users consented to exporting and metadata for which users were in a group DM together. This vulnerability is fixed in 10.0.

AnalysisAI

Zulip server provides an open-source team chat that helps teams stay productive and focused. Rated medium severity (CVSS 4.6), this vulnerability is remotely exploitable, low attack complexity. No vendor patch available.

Technical ContextAI

This vulnerability is classified under CWE-497. Zulip server provides an open-source team chat that helps teams stay productive and focused. Prior to 10.0, the data export to organization administrators feature in Zulip leaks private data. The collection of user-agent types identifying specific integrations or HTTP libraries (E.g., ZulipGitlabWebhook, okhttp, or PycURL) that have been used to access any organization on the server was incorrectly included in all three export types, regardless of if they were used to access the exported organization or not. The "public data" and "with consent" exports metadata including the titles of some topics in private channels which the administrator otherwise did not have access to, and none of the users consented to exporting and metadata for which users were in a group DM together. This vulnerability is fixed in 10.0. Affected products include: Zulip Zulip Server. Version information: Prior to 10.0.

RemediationAI

No vendor patch is available at time of analysis. Monitor vendor advisories for updates. Apply vendor patches when available. Implement network segmentation and monitoring as interim mitigations.