An improper authentication and path traversal vulnerability exists in ASUSTOR Backup Plan and ASUSTOR EZ Sync. (CVE-2026-18759) | HOL Guard CVE

High · CVSS 8.5CVE-2026-18759

An improper authentication and path traversal vulnerability exists in ASUSTOR Backup Plan and ASUSTOR EZ Sync.

Answer in brief

CVE-2026-18759 records a High severity (CVSS 8.5) vulnerability in An improper authentication and path traversal vulnerability exists in ASUSTOR Backup Plan and ASUSTOR EZ Sync.. The current sources do not mark it as known exploited. The current feed maps ASUSTOR Inc./ABP (generic), ASUSTOR Inc./AES (generic). Check affected ranges and fixed versions before updating.

Analysis pending evidence review

HOL Guard separates source facts from reviewed analysis. See the methodology.

Published Aug 4, 2026Updated Sep 3, 2026Source checked Sep 19, 2026First seen by HOL Aug 4, 2026Material review Sep 3, 2026

Upstream Advisory

Key facts

Risk: High · CVSS 8.5
Exploitation: Not marked as known exploited
Affected software: 2 mapped packages or products
Fix availability: Not reported

Why this deserves its current priority

CVSS is 8.5. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.

Analysis status

Analysis pending evidence review

Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.

Affected scope and exposure questions

The current feed maps ASUSTOR Inc./ABP (generic), ASUSTOR Inc./AES (generic). Check affected ranges and fixed versions before updating.

Mapped affected packages and fixed versions
Package	Affected range	Fixed version
ASUSTOR Inc./ABPgeneric	ABP 2.0	Not reported
ASUSTOR Inc./AESgeneric	AES 1.0	Not reported

Recommended response

Check inventory. Check lockfiles and deployed manifests for ASUSTOR Inc./ABP, ASUSTOR Inc./AES.
Review the reported fix. Monitor this advisory for an available fix and review any installs of the affected package.

Evidence timeline and material changes

Published upstream
Aug 4, 2026
Evidence: source:cvelist:source_dates:source-dates:record
Source modified
Sep 3, 2026
Evidence: source:cvelist:source_dates:source-dates:record
First seen by HOL
Aug 4, 2026

Sources and claim methodology

Source referenceasustor.com

Upstream source description

The background service of ABP or AES runs as NT AUTHORITY\SYSTEM and implements a file-based inter-process communication (IPC) mechanism protected by AES encryption. Because the encryption key file is readable by standard users and protected using DPAPI. Any authenticated local user can recover the key and forge valid IPC requests. Furthermore, the service does not check the identity of the requesting process and validates destination paths using an insufficient substring check. A local attacker can submit crafted encrypted requests containing directory traversal sequences to perform arbitrary file reads and arbitrary file writes as NT AUTHORITY\SYSTEM, leading to full local privilege escalation. Affected products and versions include: ABP (ASUSTOR Backup Plan) 2.0.7.10171 and earlier as well as AES (ASUSTOR EZSync) 1.1.1.3113 and earlier.

Quoted source text, attributed separately from HOL analysis.