CVE-2024-41926Network attack vector

Synced-user provenance forgery via unchecked RemoteId

Published Aug 1, 2024 · Updated Aug 1, 2024

Origin validation failure in Mattermost 9.5.0 through 9.5.6 and 9.9.0 allows remote authenticated users to falsify synced-user provenance. The shared-channel upsertSyncUser path accepted a sync message user RemoteId without checking that it matched the existing user’s remote association. Control of a connected remote was required, and a successful update rewrote identity provenance so the user appeared to originate from another remote.

CVSS severity2.7
Low
EPSS probability0.18%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Origin validation failure in Mattermost 9.5.0 through 9.5.6 and 9.9.0 allows remote authenticated users to falsify synced-user provenance. The shared-channel upsertSyncUser path accepted a sync message user RemoteId without checking that it matched the existing user’s remote association. Control of a connected remote was required, and a successful update rewrote identity provenance so the user appeared to originate from another remote.

The record

CVE
CVE-2024-41926
Published
Aug 1, 2024
Updated
Aug 1, 2024
Vendor
Mattermost
Product
Mattermost
Classifications
CWE-284, CWE-346, T1036
Attack vector
network
Privileges
admin

Timeline

How it unfolded

  1. Aug 1, 2024CVE publishedPublication date reported by the CVE source.
  2. Aug 1, 2024Record 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=9.5.0 <=9.5.6
  2. Affected versionversion=9.9.0

What conditions does exploitation require?

Attack vectornetwork
Required privilegesadmin

What is affected?

Mattermost · Mattermostversion=9.5.0 <=9.5.6; version=9.9.0

Published CVSS scores

4.3NIST NVDCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N
5.1GitHubCVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:N/VI:N/VA:N/SC:N/SI:L/SA:N
2.7Mattermost, Inc.CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:L/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 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesadmin
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-284Improper Access Control
CWE-346Origin Validation Error
T1036Masquerading

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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