Cyber Resilience

CVE-2025-66921

HighPublic PoC

Published: 17 December 2025

Published
17 December 2025
Modified
18 December 2025
KEV Added
Patch
CVSS Score v3.1 7.2 CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H
EPSS Score 0.0029 52.8th percentile
Risk Priority 15 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2025-66921 is a high-severity Improper Input Validation (CWE-20) vulnerability in Opensourcepos Open Source Point Of Sale. Its CVSS base score is 7.2 (High).

Operationally, ranked in the top 47.2% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.

EU & UK References

Vulnerability details

A Cross-site scripting (XSS) vulnerability in Create/Update Item(s) Module in Open Source Point of Sale v3.4.1 allows remote attackers to inject arbitrary web script or HTML via the "name" parameter.

CWE(s)

Related Threats

No named actor attribution yet. ATT&CK technique mapping in progress for this CVE.

Affected Assets

opensourcepos
open source point of sale
3.4.1

Mitigating Controls

Likely Mitigating Controls AI

Per-CVE control mapping for this CVE has not run yet; the list below is derived from the weakness types (CWEs) cited in the NVD entry.

addresses: CWE-20 CWE-79

Directly implements checks on information inputs to reject invalid data before processing.

addresses: CWE-79

Penetration testing submits XSS payloads to web applications, detecting cross-site scripting flaws for subsequent remediation.

addresses: CWE-20

Security testing and developer training directly verify and enforce proper input validation, reducing exploitability of injection and malformed-data weaknesses.

addresses: CWE-20

Security testing and evaluation at multiple SDLC stages directly detects missing or flawed input validation, with the required remediation process ensuring fixes are applied.

addresses: CWE-79

Output validation against expected content can reject or sanitize script content in generated web pages, reducing XSS exploitability.

addresses: CWE-20

Spam protection mechanisms perform filtering and detection on inbound/outbound messages, directly compensating for missing or weak input validation of unsolicited content.

References