CVE-2025-49222Network attack vector

Arbitrary file placement via unsanitized upload filename

Published Aug 21, 2025 · Updated Aug 21, 2025

Path traversal in affected Mattermost Server releases allows remote authenticated system administrators to place uploaded files arbitrarily. The createUpload handler passed an upload-session Filename containing traversal segments into path construction without reducing it to a base name. Exploitation requires system-administrator access and a shared channel linked to a remote cluster, and file placement can escape the intended attachment path.

CVSS severity6.8
Medium
EPSS probability0.30%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Path traversal in affected Mattermost Server releases allows remote authenticated system administrators to place uploaded files arbitrarily. The createUpload handler passed an upload-session Filename containing traversal segments into path construction without reducing it to a base name. Exploitation requires system-administrator access and a shared channel linked to a remote cluster, and file placement can escape the intended attachment path.

The record

CVE
CVE-2025-49222
Published
Aug 21, 2025
Updated
Aug 21, 2025
Vendor
Mattermost
Product
Mattermost
Classifications
CWE-434, T1105
Attack vector
network
Privileges
admin

Timeline

How it unfolded

  1. Aug 21, 2025CVE publishedPublication date reported by the CVE source.
  2. Aug 21, 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=10.10.0 <=10.10.0
  2. Affected versionversion=10.5.0 <=10.5.8
  3. Affected versionversion=10.8.0 <=10.8.3
  4. Affected versionversion=10.9.0 <=10.9.2
  5. Affected versionversion=9.11.0 <=9.11.17

What conditions does exploitation require?

Attack vectornetwork
Required privilegesadmin

What is affected?

Mattermost · Mattermostversion=10.10.0 <=10.10.0; version=10.5.0 <=10.5.8; version=10.8.0 <=10.8.3; version=10.9.0 <=10.9.2; version=9.11.0 <=9.11.17

Published CVSS scores

6.8NIST NVDCVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:N/I:H/A:N
6.8Mattermost, Inc.CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/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 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-434Unrestricted Upload of File with Dangerous Type
T1105Ingress Tool Transfer

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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