Cyber Posture

CVE-2026-9227

High
Microsoft: not affectedMSmacOS: not affectedMacLinux: not affectedLnxMobile: not affectedMobNetwork: not affectedNetApplication: not affectedAppOther: affectedOth

Published: 28 May 2026

Published
28 May 2026
Modified
28 May 2026
KEV Added
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Patch
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CVSS Score 8.8 CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
EPSS Score 0.0014 33.9th percentile
Risk Priority 18 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2026-9227 is a high-severity Unrestricted Upload of File with Dangerous Type (CWE-434) vulnerability in Wordpress (inferred from references). Its CVSS base score is 8.8 (High).

Operationally, exploitation aligns with the MITRE ATT&CK technique Exploit Public-Facing Application (T1190); ranked at the 33.9th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.

Threat & Defense at a Glance

What attackers do: exploitation maps to Exploit Public-Facing Application (T1190) and 1 other technique.
Threat & Defense Details

Likely Mitigating ControlsAI

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.

MP-7 Media Use
addresses: CWE-434

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

SC-44 Detonation Chambers
addresses: CWE-434

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

SC-51 Hardware-based Protection
addresses: CWE-434

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

SI-3 Malicious Code Protection
addresses: CWE-434

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

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?

Arbitrary file upload flaw in public-facing WordPress plugin directly enables web shell deployment (T1505.003) via exploitation of the application (T1190).

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

NVD Description

The GutenBee – Gutenberg Blocks plugin for WordPress is vulnerable to Arbitrary File Upload in all versions up to, and including, 2.20.1 via the gutenbee_file_and_ext_json function. This is due to a flawed strpos() substring check that only verifies whether the…

more

filename contains the string '.json' rather than confirming the filename ends with a .json extension, allowing double-extension filenames like shell.json.php to bypass validation. This makes it possible for authenticated attackers, with author-level access and above, to upload files that may be executable, which makes remote code execution possible.

Deeper analysisAI

Automated synthesis unavailable for this CVE.

Details

CWE(s)
CWE-434
OWASP Top 10 Web 2025
A06:2025

Affected Products

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

EU & UK References

References