# CVE-2026-18759: An improper authentication and path traversal vulnerability exists in ASUSTOR Backup Plan and ASUSTOR EZ Sync.

> Local attackers can escalate privileges to SYSTEM by exploiting weak IPC authentication and path traversal in ASUSTOR Backup Plan and EZ Sync.

- **Severity:** High 8.5 (`CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 4 Aug 2026
- **Updated:** 4 Aug 2026
- **Also known as:** GHSA-2p27-7hcf-mpp3

## What is CVE-2026-18759?

CVE-2026-18759 is a high-severity vulnerability in ASUSTOR Inc. ABP, published on 4 Aug 2026. It can only be exploited from the same machine or local network, with no action from the victim.

### Official 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.

Weakness: CWE-287 (Improper Authentication), CWE-269 (Improper Privilege Management)

## Which versions are affected by CVE-2026-18759?


## How do I fix CVE-2026-18759?

No fix has been published for CVE-2026-18759 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-18759 being exploited?

There is no known exploitation of CVE-2026-18759 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-18759 and fix it if it is affected.

What it is: CVE-2026-18759 is a high-severity vulnerability in ASUSTOR Inc. ABP, published on 4 Aug 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-18759 in the wild and no public exploit code.

Affected product: ASUSTOR Inc. ABP. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-18759/ (Markdown: https://insights.sbomify.com/CVE-2026-18759/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-18759
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-18759
- OSV: https://osv.dev/vulnerability/CVE-2026-18759

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-18759/
Summaries are generated and may contain mistakes; the official description above is the record.