# CVE-2026-18187: ASUSTOR ADM format string vulnerability in Internal Backup

Source: https://junglewise.ai/threats/cve-2026-18187-asustor-adm-format-string-vulnerability-in-internal-backup  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-07-30. Updated: 2026-07-30  
License: CC BY 4.0 with a link back

CVE-2026-18187 · Severity: info · CVSS 7.1 · Published 2026-07-30

ASUSTOR Data Master (ADM), the operating system used for ASUSTOR network-attached storage (NAS) devices, contains a security vulnerability in its Internal Backup feature. An authorized user can provide specially crafted input that causes the system to crash or potentially leak sensitive information from the device's memory. This could lead to a disruption of backup services or unauthorized access to technical data stored in the system's memory.

Technologies: [ASUSTOR ADM](https://junglewise.ai/threats/technologies/adm). Vendors: [ASUSTOR](https://junglewise.ai/threats/vendors/asustor).

## Quick answers

**Is CVE-2026-18187 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-18187 being exploited in the wild.

**How severe is CVE-2026-18187?** Informational severity, with a CVSS score of 7.1, published 30 July 2026.

**Which products and versions are affected?** ASUSTOR ADM 4.1.0 through 4.3.3.RUN1, 5.0.0 through 5.1.3.RI81.

**Is there a fix for CVE-2026-18187?** No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.

**How is CVE-2026-18187 attacked?** It is attacked over the network, in an operating system.

**Am I affected by CVE-2026-18187?** Check whether you run ASUSTOR ADM at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## Technical details

A format string vulnerability (CWE-134) exists in the Internal Backup component of ASUSTOR ADM. The flaw occurs when user-controlled task input is included in an error response and subsequently processed through an unsafe format string operation within a CGI process. An authenticated attacker with network access can exploit this by submitting malicious input to trigger the vulnerability. Successful exploitation can lead to the disclosure of sensitive memory information or a denial of service (DoS) by crashing the affected CGI process. The vulnerability affects ADM versions 4.1.0 through 4.3.3.RUN1 and 5.0.0 through 5.1.3.RI81.

## Affected products

- ASUSTOR ADM 4.1.0 through 4.3.3.RUN1, 5.0.0 through 5.1.3.RI81

## Timeline

- 2026-07-30: advisory

## References

- [https://www.asustor.com/security/security_advisory_detail?id=67](https://www.asustor.com/security/security_advisory_detail?id=67)

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