A newly disclosed vulnerability in Microsoft Edge is raising alarms across the cybersecurity community, and if you haven’t patched your browser yet, you’re already behind.
Microsoft officially published CVE-2026-45492 on May 15, 2026, detailing a Security Feature Bypass vulnerability stemming from improper input validation in the Chromium-based Edge browser.
The flaw carries a CVSS 3.1 base score of 5.4 (Moderate), but Microsoft’s own exploitability index flags it as “Exploitation More Likely,“ a classification that commands immediate enterprise attention despite the moderate severity label.
At its core, CVE-2026-45492 is an Improper Input Validation flaw (CWE-20) that allows an unauthorized remote attacker to bypass critical security protections in Microsoft Edge.
The attack vector is network-based, requires no elevated privileges, and demands only minimal user interaction, making it accessible to a broad range of threat actors.
Microsoft Edge Flaw
Microsoft’s executive summary confirms: “Improper input validation in Microsoft Edge (Chromium-based) allows an unauthorized attacker to bypass a security feature over a network.”
The vulnerability’s CVSS vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:N reveals the full technical picture:
- Attack Vector: Network – no physical access required
- Attack Complexity: Low – exploitation does not require special conditions
- Privileges Required: None – any unauthenticated attacker can attempt it
- User Interaction: Required – victim must interact (e.g., visit a malicious page)
- Confidentiality & Integrity: Low impact – data exposure and modification possible
- Availability: No impact – no service disruption expected
What makes CVE-2026-45492 particularly dangerous is which security feature can be bypassed. According to Microsoft’s own FAQ, an authenticated local attacker can turn Windows Virtualization-Based Security (VBS) on or off without administrative privileges, effectively stripping one of Windows’ most critical platform security hardening mechanisms.
VBS uses hardware virtualization to create an isolated memory region that protects sensitive system processes. When VBS is disabled, the door swings open to follow-on attacks, including credential theft, kernel exploits, and privilege escalation chains, even though CVE-2026-45492 itself doesn’t grant direct code execution.
This is consistent with a broader attack pattern observed by security researchers at DEVCORE, where browser-level logic flaws are deliberately chained to weaken the underlying OS before delivering a payload.
CVE-2026-45492 was responsibly disclosed through coordinated vulnerability disclosure. Microsoft acknowledges both an anonymous reporter and Orange Tsai of the DEVCORE Research Team, working with the TrendAI Zero Day Initiative.
The Zero Day Initiative (ZDI), now operating under TrendAI, acts as a critical bridge between independent researchers and vendors, ensuring vulnerabilities are patched before weaponized exploits surface in the wild.
At the time of publication, the vulnerability had not been publicly exploited, and no exploit code had been confirmed in the wild, but the “Exploitation More Likely” designation from Microsoft’s MSRC reflects the belief that threat actors could realistically develop a working exploit given the low complexity and network-based attack vector.
Affected Versions
The vulnerability affects all versions of Microsoft Edge (Chromium-based) before 148.0.3967.70, released on May 15, 2026. This stable channel update is built on Chromium version 148.0.7778.168 and bundles multiple additional security fixes tied to the broader May 2026 Patch Tuesday release cycle.
Tenable’s Nessus Plugin ID 315006 flags all remote Windows hosts running Edge versions below this threshold as vulnerable, including configurations deployed in enterprise environments. GovCERT Hong Kong and HKCERT have also issued independent security bulletins urging immediate patching.
Remediation
Patching CVE-2026-45492 is straightforward. Follow these steps:
- Open Microsoft Edge and navigate to
edge://settings/help - Edge will automatically check for updates and prompt installation of version 148.0.3967.70
- Restart the browser to apply the fix.
- Enterprise administrators can deploy updates via Microsoft Update Catalog (Build 148.0.3967.70) or through Intune/WSUS policies.
- Verify the installed version post-update via
edge://version
Organizations should cross-reference this fix with the full May 2026 Patch Tuesday advisory, which addressed 137 separate vulnerabilities across Microsoft products.
For security teams conducting risk triage, CVE-2026-45492 should be treated with elevated urgency despite its “Moderate” CVSS label.
The combination of low attack complexity, no privilege requirements, network accessibility, and VBS bypasses creates a viable launchpad for multi-stage attacks, particularly in environments where Edge is the default enterprise browser.
Defenders should also monitor for suspicious Edge process behaviors, unexpected VBS state changes, and anomalous browser network activity as potential indicators of exploitation attempts.
FAQ
Q1: What is CVE-2026-45492?
It is a Moderate-severity Security Feature Bypass flaw in Microsoft Edge caused by improper input validation (CWE-20), assigned a CVSS score of 5.4.
Q2: Is CVE-2026-45492 actively exploited in the wild?
No. As of May 15, 2026, Microsoft confirms there is no public exploitation, though it rates the flaw as “Exploitation More Likely.”
Q3: Which Edge version fixes CVE-2026-45492?
Microsoft Edge version 148.0.3967.70, released May 15, 2026, contains the official patch for this vulnerability.
Q4: Who discovered CVE-2026-45492?
The flaw was reported by an anonymous researcher and Orange Tsai of DEVCORE Research Team, working with the TrendAI Zero Day Initiative.
Site: thecybrdef.com
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