Time-of-check Time-of-use (TOCTOU) Race Condition in Microsoft Edge - CVE-2026-66314

Vulnerability details

The vulnerability allows a remote attacker to disclose sensitive information.

The vulnerability exists due to a time-of-check time-of-use race condition in Microsoft Edge (Chromium-based) autofill handling when processing an attacker-controlled webpage and autofill activation gestures. A remote attacker can cause the victim to visit a crafted webpage and perform two tap gestures to disclose sensitive information.

User interaction is required: the victim must visit the attacker-controlled webpage and perform the two tap gestures that cause autofill to activate.

Affected software

How to mitigate CVE-2026-66314

External References

• https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2026-66314
• https://docs.microsoft.com/en-us/DeployEdge/microsoft-edge-relnotes-security

Related Security Bulletins

• Multiple vulnerabilities in Microsoft Edge