CVE-2026-21628

Critical

Published: 05 March 2026

Published

05 March 2026

Modified

13 March 2026

KEV Added

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Patch

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CVSS Score 9.8 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

EPSS Score 0.0027 50.0th percentile

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

Summary

CVE-2026-21628 is a critical-severity Unrestricted Upload of File with Dangerous Type (CWE-434) vulnerability in Templaza Astroid Framework. Its CVSS base score is 9.8 (Critical).

Operationally, exploitation aligns with the MITRE ATT&CK technique Exploit Public-Facing Application (T1190); ranked at the 50.0th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.

The strongest mitigations our analysis identified are NIST 800-53 AC-3 (Access Enforcement) and SI-10 (Information Input Validation).

Threat & Defense at a Glance

What attackers do: exploitation maps to Exploit Public-Facing Application (T1190). What defenders deploy: see the NIST 800-53 controls recommended below.

Threat & Defense Details

Mitigating Controls (NIST 800-53 r5)AI

SI-10 Information Input Validation good match

prevent

SI-10 requires validation of information inputs, directly preventing uploads of dangerous data types that enable remote code execution.

AC-3 Access Enforcement good match

prevent

AC-3 enforces approved authorizations, preventing unauthenticated users from accessing the vulnerable file management feature.

SI-9 Information Input Restrictions good match

prevent

SI-9 restricts types and content of information inputs to systems, blocking dangerous file uploads at the boundary.

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 →

Why these techniques?

The vulnerability allows unauthenticated remote code execution via exploitation of a public-facing file management feature, directly mapping to T1190: Exploit Public-Facing Application.

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

NVD Description

A improperly secured file management feature allows uploads of dangerous data types for unauthenticated users, leading to remote code execution.

Deeper analysisAI

CVE-2026-21628 is a vulnerability in an improperly secured file management feature that allows unauthenticated users to upload dangerous data types, leading to remote code execution. Published on 2026-03-05, it carries a CVSS v3.1 base score of 9.8 (AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H) and is categorized under CWE-434.

Unauthenticated attackers with network access can exploit this vulnerability with low complexity and no user interaction required. Successful exploitation enables remote code execution, granting high levels of confidentiality, integrity, and availability impact on the affected system.

Mitigation details are available in the referenced advisory at https://astroidframe.work.