CVE-2026-18188Network attack vector

Memory disclosure or service interruption via format strings

Published Jul 30, 2026 · Updated Jul 30, 2026

Format-string injection in ASUSTOR Data Master Rsync Backup allows remote authenticated users to disclose memory or interrupt backup service. The backup component passes user-controlled rsync configuration or log data to an unsafe format string operation instead of treating it solely as data. Valid ADM credentials and network access are required; affected releases are 4.1.0 through 4.3.3.RUN1 and 5.0.0 through 5.1.3.RI81, and exploitation can crash the component.

CVSS severity7.1
High
EPSS probability0.27%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Format-string injection in ASUSTOR Data Master Rsync Backup allows remote authenticated users to disclose memory or interrupt backup service. The backup component passes user-controlled rsync configuration or log data to an unsafe format string operation instead of treating it solely as data. Valid ADM credentials and network access are required; affected releases are 4.1.0 through 4.3.3.RUN1 and 5.0.0 through 5.1.3.RI81, and exploitation can crash the component.

The record

CVE
CVE-2026-18188
Published
Jul 30, 2026
Updated
Jul 30, 2026
Vendor
ASUSTOR Inc.
Product
ASUSTOR Data Master
Classifications
CWE-134, CAPEC-135, T1499
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Jul 30, 2026CVE publishedPublication date reported by the CVE source.
  2. Jul 30, 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=4.1.0 <=4.3.3.RUN1
  2. Affected versionversion=5.0.0 <=5.1.3.RI81

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

ASUSTOR Inc. · ASUSTOR Data Masterversion=4.1.0 <=4.3.3.RUN1; version=5.0.0 <=5.1.3.RI81

Published CVSS scores

7.1ASUSTOR Inc.CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:N/VA:H/SC:N/SI:N/SA:N
8.1NIST NVDCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H

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 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-134Use of Externally-Controlled Format String
CAPEC-135Format String Injection
T1499Endpoint Denial of Service

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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