Reference page — cumulative record through Sunday, October 4, 2026 UTC. Reference pages update as the archive grows; only dated daily editions are immutable pages of record.

CVE-2026-74239

CVE-2026-74239HIGH

XenForo < 2.3.13 Path Traversal via Style Archive Importer on Windows

  AV  AC  AT  PR  UI  VC  VI  VA   CVSS    EPSS   %ile   KEV
   N   L   N   H   N   H   H   H    8.6   .0089   57.9     —

AFFECTED
  Product  Versions     Fixed
  XenForo  unspecified  —

TIMELINE
  Aug 14  Reserved by VulnCheck
  Sep 8   Published (CNA: VulnCheck)
  Sep 9   EXPLOIT PUBLISHED — CVE-2026-74239 (XenForo). Public exploit reference added.
  Sep 11  EXPLOIT PUBLISHED — CVE-2026-74239 (XenForo). Public exploit reference added.

CWE-22 · CNA: VulnCheck · CVSS v4.0 · 5 references · NVD status: Analyzed

Description

XenForo before 2.3.13 contains a path traversal vulnerability in the style archive importer on Windows deployments that allows authenticated non-super administrators with style permissions to write arbitrary files outside the intended extraction directory by using backslash-based traversal sequences in ZIP member names. Attackers can craft a malicious ZIP archive with backslash path separators that bypass forward-slash validation to write arbitrary bytes to any web-server-writable path, including the public web root, achieving persistent code execution as the web-server account.

Lifecycle

Complete event history — 4 events, chronological
Date	Event	Detail
August 14, 2026	Reserved	Reserved by VulnCheck
September 8, 2026	Published	Published (CNA: VulnCheck)
September 9, 2026	EXPLOIT PUBLISHED	EXPLOIT PUBLISHED — CVE-2026-74239 (XenForo). Public exploit reference added.
September 11, 2026	EXPLOIT PUBLISHED	EXPLOIT PUBLISHED — CVE-2026-74239 (XenForo). Public exploit reference added.

Affected

Affected products and packages — 1 row
Vendor	Product / Package	Ecosystem	Version introduced	Fixed
XenForo	XenForo	—	—	—

Weaknesses

CWE-22

References (5)

https://bombobombone.github.io/posts/cve-2026-74239/ [technical-description]
https://github.com/BomboBombone/CVE-2026-74239 [exploit]
https://www.vulncheck.com/advisories/xenforo-path-traversal-via-style-archive-importer-on-windows [third-party-advisory]
https://xenforo.com/community/threads/security-fixes-released-for-all-xenforo-and-media-gallery-versions-2-2-0-2-3-12.239856/ [vendor-advisory, patch]
https://xenforo.com/community/threads/xenforo-2-3-13-and-add-ons-released-includes-security-fixes.239857/ [release-notes]

Authoritative record: CVE-2026-74239 at cve.org

Vendors: xenforo

Weaknesses: CWE-22

About this page

This is a reference page, not a dated page of record. It assembles the complete lifecycle of CVE-2026-74239 from the CVE Program record, NVD enrichment, the CISA KEV catalog, EPSS, and OSV advisories. The box score's numbers (CVSS, EPSS, KEV status) are current as of Sunday, October 4, 2026 UTC and are re-derived as the archive grows; only dated daily editions are immutable pages of record. The authoritative source for this identifier is cve.org.