CVE-2026-9550

Medium

Published: 26 May 2026

Published

26 May 2026

Modified

26 May 2026

KEV Added

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Patch

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CVSS Score v4 5.5 CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N/E:P/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 0.0050 38.9th percentile

Risk Priority 11 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2026-9550 is a medium-severity Path Traversal (CWE-22) vulnerability in Feishu (inferred from references). Its CVSS base score is 5.5 (Medium).

Operationally, exploitation aligns with the MITRE ATT&CK technique Exploit Public-Facing Application (T1190); ranked at the 38.9th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.

EU & UK References

🇪🇺 ENISA EUVD: EUVD-2026-31825

Vulnerability details

A vulnerability was determined in Acrel Electrical EEMS Enterprise Power Operation and Maintenance Cloud Platform 1.3.0. Affected by this issue is some unknown functionality of the file /SubstationWEBV2/app/..;/main/upfile. Executing a manipulation of the argument path can lead to path traversal.…

The attack may be performed from remote. The exploit has been publicly disclosed and may be utilized. The vendor was contacted early about this disclosure but did not respond in any way.

CWE(s): CWE-22

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.

attack.mitre.org →

T1505.003 Web Shell Persistence

Adversaries may backdoor web servers with web shells to establish persistent access to systems.

attack.mitre.org →

Why these techniques?

Remote path traversal on a public-facing file upload endpoint (upfile) directly enables exploitation of the web application (T1190) and deployment of web shells for persistence/execution (T1505.003).

Confidence: HIGH · MITRE ATT&CK Enterprise v18.1