How severe is CVE-2025-15559?

CVE-2025-15559 has a CVSS 3.x base score of 9.8, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2025-15559 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (35th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2025-15559?

CVE-2025-15559 primarily affects Nestersoft Worktime. In total, 2 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2025-15559?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.

Does CVE-2025-15559 have an EU (EUVD) identifier?

Yes. CVE-2025-15559 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2025-207634.

When was CVE-2025-15559 published?

CVE-2025-15559 was published on 2026-02-19 and last updated on 2026-06-17.

CVE-2025-15559

CVE-2025-15559 is a critical-severity vulnerability in Nestersoft Worktime with a CVSS 3.x base score of 9.8. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-78.

Key facts

Severity: Critical (CVSS 3.x base score 9.8)
EPSS exploit prediction: 0% (35th percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2025-207634
Weakness: CWE-78
Affected product: Nestersoft Worktime
Published: 2026-02-19
Last modified: 2026-06-17

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.

Frequently asked questions

What is CVE-2025-15559?: 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.
How severe is CVE-2025-15559?: CVE-2025-15559 has a CVSS 3.x base score of 9.8, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2025-15559 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (35th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2025-15559?: CVE-2025-15559 primarily affects Nestersoft Worktime. In total, 2 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2025-15559?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.
Does CVE-2025-15559 have an EU (EUVD) identifier?: Yes. CVE-2025-15559 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2025-207634.
When was CVE-2025-15559 published?: CVE-2025-15559 was published on 2026-02-19 and last updated on 2026-06-17.

References

https://r.sec-consult.com/worktime

Affected products (2)

cpe:2.3:a:nestersoft:worktime:*:*:*:*:cloud:*:*:*
cpe:2.3:a:nestersoft:worktime:*:*:*:*:on-premise:*:*:*

More vulnerabilities in Nestersoft Worktime

CVE-2025-15560 — High (CVSS 8.8): An authenticated attacker with minimal permissions can exploit a SQL injection in the WorkTime server "widget" API…
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CVE-2025-15562 — Medium (CVSS 6.1): The server API endpoint /report/internet/urls reflects received data into the HTML response without applying proper…
CVE-2025-15563 — Medium (CVSS 5.3): Any unauthenticated user can reset the WorkTime on-prem database configuration by sending a specific HTTP request to…

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