Cyber Resilience

CVE-2026-21627

Critical

Published: 20 February 2026

Published
20 February 2026
Modified
15 April 2026
KEV Added
Patch
CVSS Score v4 9.5 CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H/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 0.0040 31.4th percentile
Risk Priority 70 floored blend · peak EPSS

Summary

CVE-2026-21627 is a critical-severity Improper Access Control (CWE-284) vulnerability in Tassos Framework (inferred from references). Its CVSS base score is 9.5 (Critical).

Operationally, ranked at the 31.4th 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

The vulnerability was rooted in how the Tassos Framework plugin handled specific AJAX requests through Joomla’s com_ajax entry point. Under certain conditions, internal framework functionality could be invoked without proper restriction.

CWE(s)

Related Threats

No named actor attribution yet. ATT&CK technique mapping in progress for this CVE.

Affected Assets

Tassos
Framework
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

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.

addresses: CWE-284

Requiring prior authorization for each remote access type prevents improper access control over remote connections.

addresses: CWE-284

Requiring authorization of wireless access before allowing connections enforces proper access control for this access method.

References