CVE-2025-15559

Unauthenticated OS Command Injection in NesterSoft WorkTime

Published Feb 19, 2026 CVSS 3.1 · 9.8 Critical EPSS < 1% KEV · Not listed
Description
An unauthenticated attacker can inject OS commands when calling a server API endpoint in NesterSoft WorkTime. The server API call to generate and download the WorkTime client from the WorkTime server is vulnerable in the “guid” parameter. This allows an attacker to execute arbitrary commands on the WorkTime server as NT Authority\SYSTEM with the highest privileges. Attackers are able to access or manipulate sensitive data and take over the whole server.

Remediation

Vendor Solution

The vendor did not respond to our communication attempts anymore. It is currently as of February 2026 unclear, whether a patch is available. Please contact the vendor to request a patch for the identified critical security issues.

Tracking

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Advisories

No advisories available
References
History
Type Values Removed Values Added
CPEs cpe:2.3:a:nestersoft:worktime:*:*:*:*:cloud:*:*:*
cpe:2.3:a:nestersoft:worktime:*:*:*:*:on-premise:*:*:*
Type Values Removed Values Added
Metrics cvssV3_1

{'score': 9.8, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H'}

ssvc

{'options': {'Automatable': 'yes', 'Exploitation': 'poc', 'Technical Impact': 'total'}, 'version': '2.0.3'}

Type Values Removed Values Added
First Time appeared Nestersoft
Nestersoft worktime
Vendors & Products Nestersoft
Nestersoft worktime
Type Values Removed Values Added
Description An unauthenticated attacker can inject OS commands when calling a server API endpoint in NesterSoft WorkTime. The server API call to generate and download the WorkTime client from the WorkTime server is vulnerable in the “guid” parameter. This allows an attacker to execute arbitrary commands on the WorkTime server as NT Authority\SYSTEM with the highest privileges. Attackers are able to access or manipulate sensitive data and take over the whole server.
Title Unauthenticated OS Command Injection in NesterSoft WorkTime
Weaknesses CWE-78
References
Weaknesses

Sources

Status
PUBLISHED
Assigner
SEC-VLab
Published
Updated
Feb 23, 2026, 6:30 PM
Reserved
Feb 4, 2026, 7:44 AM
Status
Analyzed
Published
Feb 19, 2026, 11:15 AM
Modified
Jun 17, 2026, 8:38 AM