CVE-2026-9824Network attack vector

Remote cluster metadata disclosure via missing authorization

Published Jul 13, 2026 · Updated Jul 13, 2026

Missing authorization in Mattermost allows remote authenticated users to disclose configured remote cluster connection metadata via autocomplete. The /share-channel autocomplete handler returns remote-cluster connection details without checking manage_shared_channels. Any authenticated account that can invoke slash-command autocomplete can enumerate those connections despite lacking the management permission; no modification or service interruption is reported.

CVSS severity4.3
Medium
EPSS probability0.27%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Missing authorization in Mattermost allows remote authenticated users to disclose configured remote cluster connection metadata via autocomplete. The /share-channel autocomplete handler returns remote-cluster connection details without checking manage_shared_channels. Any authenticated account that can invoke slash-command autocomplete can enumerate those connections despite lacking the management permission; no modification or service interruption is reported.

The record

CVE
CVE-2026-9824
Published
Jul 13, 2026
Updated
Jul 13, 2026
Vendor
Mattermost
Product
Mattermost
Classifications
CWE-862
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Jul 13, 2026CVE publishedPublication date reported by the CVE source.
  2. Jul 13, 2026Record 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=10.11.0 <=10.11.19
  2. Affected versionversion=11.6.0 <=11.6.4
  3. Affected versionversion=11.7.0 <=11.7.2

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

Mattermost · Mattermostversion=10.11.0 <=10.11.19; version=11.6.0 <=11.6.4; version=11.7.0 <=11.7.2

Published CVSS scores

4.3Mattermost, Inc.CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/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.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-862Missing Authorization

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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