CVE-2025-15559Network attack vector

Unauthenticated SYSTEM command execution via crafted guid

Published Feb 19, 2026 · Updated Feb 19, 2026

OS command injection in NesterSoft WorkTime 11.8.8 and earlier allows remote attackers to execute commands via a server API request. The client-generation and download API passes the untrusted guid parameter into an operating-system command without neutralizing command syntax. No authentication or user interaction is required, and injected commands run as NT Authority\SYSTEM, permitting server takeover and access to or modification of sensitive data.

CVSS severity9.8
Critical
EPSS probability0.44%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

OS command injection in NesterSoft WorkTime 11.8.8 and earlier allows remote attackers to execute commands via a server API request. The client-generation and download API passes the untrusted guid parameter into an operating-system command without neutralizing command syntax. No authentication or user interaction is required, and injected commands run as NT Authority\SYSTEM, permitting server takeover and access to or modification of sensitive data.

The record

CVE
CVE-2025-15559
Published
Feb 19, 2026
Updated
Feb 19, 2026
Vendor
NesterSoft Inc.
Product
WorkTime
Classifications
CWE-78, T1059.003, T1190
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Feb 19, 2026CVE publishedPublication date reported by the CVE source.
  2. Feb 19, 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=<= 11.8.8

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

NesterSoft Inc. · WorkTimeversion=<= 11.8.8

Published CVSS scores

9.8CISA-ADPCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/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
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-78Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection')
T1059.003Windows Command Shell
T1190Exploit Public-Facing Application

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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