CVE-2024-27286Network attack vector

Authenticated message disclosure via skipped access revocation

Published Mar 20, 2024 · Updated Mar 31, 2025

Access-control failure in Zulip Server 3.0 through 8.2 allows remote authenticated users to read messages moved into inaccessible private streams. An improperly indented branch in do_update_message skips UserMessage-row deletion and delete_message events for single-message moves. The reader must have previously received the message; exposure persists through search or All messages, while stale feeds persist until reload.

CVSS severity6.5
Medium
EPSS probability0.52%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Access-control failure in Zulip Server 3.0 through 8.2 allows remote authenticated users to read messages moved into inaccessible private streams. An improperly indented branch in do_update_message skips UserMessage-row deletion and delete_message events for single-message moves. The reader must have previously received the message; exposure persists through search or All messages, while stale feeds persist until reload.

The record

CVE
CVE-2024-27286
Published
Mar 20, 2024
Updated
Mar 31, 2025
Vendor
Zulip
Product
Zulip
Classifications
CWE-200, T1213.005
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Mar 20, 2024CVE publishedPublication date reported by the CVE source.
  2. Mar 31, 2025Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=>= 3.0, < 8.3

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

Zulip · Zulipversion=>= 3.0, < 8.3

Published CVSS scores

6.5GitHub, Inc.CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-200Exposure of Sensitive Information to an Unauthorized Actor
T1213.005Messaging Applications

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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