CVE-2026-3112Network attack vector

Host file read via unvalidated logging paths

Published Mar 26, 2026 · Updated Mar 26, 2026

Path traversal in Mattermost allows remote authenticated users with system-admin rights to read arbitrary host files during support packet generation. Advanced Logging accepts file-target paths from AdvancedLoggingJSON without checking that they remain inside the permitted logging directory, and the support-packet builder packages the referenced files. System-administrator privileges are required; the disclosed impact is host-file disclosure, with no reported write or service-interruption capability.

CVSS severity6.8
Medium
EPSS probability0.42%
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 Mattermost allows remote authenticated users with system-admin rights to read arbitrary host files during support packet generation. Advanced Logging accepts file-target paths from AdvancedLoggingJSON without checking that they remain inside the permitted logging directory, and the support-packet builder packages the referenced files. System-administrator privileges are required; the disclosed impact is host-file disclosure, with no reported write or service-interruption capability.

The record

CVE
CVE-2026-3112
Published
Mar 26, 2026
Updated
Mar 26, 2026
Vendor
Mattermost
Product
Mattermost
Classifications
CWE-22, T1005
Attack vector
network
Privileges
admin

Timeline

How it unfolded

  1. Mar 26, 2026CVE publishedPublication date reported by the CVE source.
  2. Mar 26, 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 <=10.11.11
  2. Affected versionversion=11.2.0 <=11.2.3
  3. Affected versionversion=11.3.0 <=11.3.1
  4. Affected versionversion=11.4.0 <=11.4.0

What conditions does exploitation require?

Attack vectornetwork
Required privilegesadmin

What is affected?

Mattermost · Mattermostversion=10.11.0 <=10.11.11; version=11.2.0 <=11.2.3; version=11.3.0 <=11.3.1; version=11.4.0 <=11.4.0

Published CVSS scores

4.9NIST NVDCVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:N/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-22Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')
T1005Data from Local System

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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