Cyber Resilience

CVE-2026-9157

High

Published: 21 May 2026

Published
21 May 2026
Modified
21 May 2026
KEV Added
Patch
CVSS Score v4 8.6 CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
EPSS Score 0.0012 2.1th percentile
Risk Priority 55 floored blend · peak EPSS

Summary

CVE-2026-9157 is a high-severity Improper Input Validation (CWE-20) vulnerability in Co (inferred from references). Its CVSS base score is 8.6 (High).

Operationally, exploitation aligns with the MITRE ATT&CK technique Exploit Public-Facing Application (T1190); ranked at the 2.1th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.

OWASP Top 10 for Web (2025)

EU & UK References

Vulnerability details

Improper input validation, Unrestricted upload of file with dangerous type vulnerability in Gmission Web Fax allows Remote Code Inclusion. This issue affects Web Fax: from 3.0 before 3.1.

CWE(s)

Related Threats

MITRE ATT&CK Enterprise TechniquesAI

T1190 Exploit Public-Facing Application Initial Access
Adversaries may attempt to exploit a weakness in an Internet-facing host or system to initially access a network.
Why these techniques?

Unrestricted file upload (CWE-434) with improper input validation in a public-facing web application directly enables remote code execution via exploitation of the exposed service.

Confidence: HIGH · MITRE ATT&CK Enterprise v19.0

CVEs Like This One

CVE-2025-22137Shared CWE-20, CWE-434
CVE-2026-2113Shared CWE-20, CWE-434
CVE-2025-68398Shared CWE-20, CWE-434
CVE-2025-12352Shared CWE-434
CVE-2026-1730Shared CWE-434
CVE-2025-13067Shared CWE-434
CVE-2025-48913Shared CWE-20
CVE-2025-67484Shared CWE-20
CVE-2025-54449Shared CWE-434
CVE-2025-1070Shared CWE-434

Affected Assets

Co
inferred from references and description; NVD did not file a CPE for this CVE

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-434

Requiring identifiable owners for portable devices reduces the attack surface for unrestricted uploads of dangerous file types via anonymous media.

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-434

Dangerous file uploads can be detonated in the chamber to determine malice before any production write or execution occurs.

addresses: CWE-434

Prevents unrestricted writing of arbitrary or malicious firmware by keeping hardware write-protect enabled except under tightly controlled manual procedures.

addresses: CWE-20

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

addresses: CWE-434

Scans files from external sources on download/open/execute, blocking unrestricted uploads of dangerous file types.

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