CVE-2026-74239Network attack vector

Code execution via backslash archive traversal

Published Sep 8, 2026 · Updated Sep 9, 2026

Path traversal in XenForo before 2.3.13 allows remote authenticated users with style permissions to execute code on Windows servers. The style archive importer checks ZIP member names for forward-slash traversal but permits backslash sequences that Windows resolves outside the extraction directory. A non-super administrator with style permissions can write arbitrary bytes to web-server-writable paths, including the public web root, as the web-server account.

CVSS severity8.6
High
EPSS probability0.69%
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 XenForo before 2.3.13 allows remote authenticated users with style permissions to execute code on Windows servers. The style archive importer checks ZIP member names for forward-slash traversal but permits backslash sequences that Windows resolves outside the extraction directory. A non-super administrator with style permissions can write arbitrary bytes to web-server-writable paths, including the public web root, as the web-server account.

The record

CVE
CVE-2026-74239
Published
Sep 8, 2026
Updated
Sep 9, 2026
Vendor
XenForo Ltd.
Product
XenForo
Classifications
CWE-22, T1505.003
Attack vector
network
Privileges
admin

Timeline

How it unfolded

  1. Sep 8, 2026CVE publishedPublication date reported by the CVE source.
  2. Sep 9, 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 <2.3.13

What conditions does exploitation require?

Attack vectornetwork
Required privilegesadmin

What is affected?

XenForo Ltd. · XenForoversion=0 <2.3.13

Published CVSS scores

7.2VulnCheckCVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H
8.6VulnCheckCVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA: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 9, 2026Sep 15, 2026
Latest reporting daySep 15, 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')
T1505.003Web Shell

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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