CVE-2025-15559 | Unauthenticated OS Command Injection in NesterSoft WorkTime

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.

Published: 2026-02-19 Last update: 2026-06-17 Assigner: 551230f0-3615-47bd-b7cc-93e92e730bbf Source: 551230f0-3615-47bd-b7cc-93e92e730bbf
NVD Status：Analyzed，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2025-15559 is rated Moderate Risk (51.7/100): CVSS Critical severity, with low exploitation likelihood (EPSS 0.44%). Review affected assets and schedule remediation.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2025-15559

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-06-15 0.15% 0.44% +0.29%
2 2026-02-25 0.12% 0.15% +0.04%
3 2026-02-24 — 0.12% —

Full EPSS history (5 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2025-15559

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
9.8 3.1 CRITICAL
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 3.9 5.9 134c704f-9b21-4f2e-91b3-4a467353bcc0

Weakness enumeration for CVE-2025-15559

Affected software / configurations for CVE-2025-15559

Vendor Product Version Raw CPE
nestersoft worktime <= 11.8.8 cpe:2.3:a:nestersoft:worktime:*:*:*:*:cloud:*:*:*
nestersoft worktime <= 11.8.8 cpe:2.3:a:nestersoft:worktime:*:*:*:*:on-premise:*:*:*

References for CVE-2025-15559

URL Tags
https://r.sec-consult.com/worktime Third Party Advisory
cvelogic Threat Intelligence