Cyber Resilience

CVE-2026-8758

Medium

Published: 17 May 2026

Published
17 May 2026
Modified
18 May 2026
KEV Added
Patch
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 0.0028 19.3th percentile
Risk Priority 11 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2026-8758 is a medium-severity Improper Access Control (CWE-284) 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 19.3th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.

EU & UK References

Vulnerability details

A vulnerability was determined in Metasoft 美特软件 MetaCRM up to 6.4.0 Beta06. This impacts an unknown function of the file /common/jsp/upload3.jsp. Executing a manipulation of the argument File can lead to unrestricted upload. The attack may be launched remotely. The…

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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)

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.
T1505.003 Web Shell Persistence
Adversaries may backdoor web servers with web shells to establish persistent access to systems.
Why these techniques?

Unrestricted file upload in public-facing web app directly enables remote exploitation (T1190) and web shell deployment (T1505.003).

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

CVEs Like This One

CVE-2024-13144Shared CWE-284, CWE-434
CVE-2025-8504Shared CWE-284, CWE-434
CVE-2025-7190Shared CWE-284, CWE-434
CVE-2025-0341Shared CWE-284, CWE-434
CVE-2026-1152Shared CWE-284, CWE-434
CVE-2025-2952Shared CWE-284, CWE-434
CVE-2026-3187Shared CWE-284, CWE-434
CVE-2024-13212Shared CWE-284, CWE-434
CVE-2025-0463Shared CWE-284, CWE-434
CVE-2026-1423Shared CWE-284, CWE-434

Affected Assets

Feishu
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-284 CWE-434

This control enforces ownership-based restrictions on portable storage device use, directly implementing access control over media insertion into organizational systems.

addresses: CWE-284 CWE-434

Hardware write-protect enforces access control on critical resources (e.g., firmware) independent of software state.

addresses: CWE-284

The access control policy and procedures directly mandate and enforce proper access control mechanisms across the organization.

addresses: CWE-284

Device lock enforces restricted access until re-authentication, directly reducing unauthorized use of active sessions.

addresses: CWE-284

Supervision and review of access control activities directly detects and remediates improper access configurations or usages.

addresses: CWE-284

Explicitly identifying and documenting actions permitted without identification or authentication enforces proper access control boundaries by defining justified exceptions.

addresses: CWE-284

By automatically labeling outputs with security attributes, the control supports attribute-based enforcement and reduces exploitability of improper access control weaknesses.

addresses: CWE-284

Associating and retaining security attributes with data directly supports enforcement of access control decisions across storage, processing, and transmission.

References