CVE-2026-75025Network attack vectorHinoki check available

Private network access via server-rendered requests

Published Sep 16, 2026 · Updated Sep 17, 2026

Origin validation error in Mattermost Desktop App 6.2.2 and earlier allows remote attackers to reach private network resources via server content. The desktop client's request filter fails to reject local and private network destinations referenced by content rendered from a connected Mattermost server. A user must connect the client to attacker-controlled or compromised server content; successful requests expose only resources reachable from that client context.

CVSS severity4.7
Medium
EPSS probability0.15%
Next 30 days · Oct 19, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkAvailable
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Summary

What happened

Origin validation error in Mattermost Desktop App 6.2.2 and earlier allows remote attackers to reach private network resources via server content. The desktop client's request filter fails to reject local and private network destinations referenced by content rendered from a connected Mattermost server. A user must connect the client to attacker-controlled or compromised server content; successful requests expose only resources reachable from that client context.

The record

CVE
CVE-2026-75025
Published
Sep 16, 2026
Updated
Sep 17, 2026
Vendor
Mattermost
Product
Mattermost
Classifications
CWE-346
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Sep 16, 2026CVE publishedPublication date reported by the CVE source.
  2. Sep 17, 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=0 <=6.2.2

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Mattermost · Mattermostversion=0 <=6.2.2

Published CVSS scores

4.7MattermostCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/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.

Activity data is delayed. The latest report is Sep 28, 2026.

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

No observations available

Sep 22, 2026Sep 28, 2026
Latest reporting daySep 28, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-346Origin Validation Error

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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