CVE-2026-21223
Published: 16 January 2026
Summary
CVE-2026-21223 is a high-severity Improper Privilege Management (CWE-269) vulnerability in Microsoft Edge Chromium. Its CVSS base score is 7.1 (High).
Operationally, exploitation aligns with the MITRE ATT&CK technique Exploitation for Privilege Escalation (T1068); ranked at the 8.0th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.
Threat & Defense at a Glance
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.
Policy addresses roles, responsibilities, and privilege management to prevent improper privilege assignments.
Access supervision ensures privileges are assigned and managed without improper escalation or retention.
Assigning group/role memberships and access authorizations (privileges) while reviewing accounts addresses improper privilege management.
Enforces proper privilege management by requiring all decisions through the verified reference monitor.
By mandating division of duties across roles, the control enforces proper privilege management and prevents a single entity from controlling an entire sensitive process.
Implements core proper privilege management by restricting to only required rights.
Policy requires training on privilege management and least privilege, making it harder to exploit improper privilege management weaknesses.
Training covers proper privilege management practices, making incorrect privilege assignments less likely.
MITRE ATT&CK Enterprise TechniquesAI
Why these techniques?
Improper privilege management in Edge enables local bypass of a security feature with low privileges, directly facilitating exploitation for privilege escalation and UAC bypass mechanisms.
NVD Description
Improper privilege management in Microsoft Edge (Chromium-based) allows an authorized attacker to bypass a security feature locally.
Deeper analysisAI
CVE-2026-21223 is an improper privilege management vulnerability affecting Microsoft Edge (Chromium-based), published on 2026-01-16T22:16:25.983. It enables an authorized attacker to bypass a security feature locally and is classified under CWE-269: Improper Privilege Management. The vulnerability has a CVSS v3.1 base score of 7.1, reflecting attack vector (AV:L), low attack complexity (AC:L), low privileges required (PR:L), no user interaction (UI:N), unchanged scope (S:U), high confidentiality impact (C:H), high integrity impact (I:H), and no availability impact (A:N).
The attack requires local access and low-level privileges, allowing exploitation with low complexity and no user interaction. A successful attacker can achieve high confidentiality and integrity impacts by bypassing the security feature, potentially leading to unauthorized data access or modification within the affected Edge environment.
Mitigation details are available in the Microsoft Security Response Center advisory at https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-21223.
Details
- CWE(s)