Time-of-check Time-of-use (TOCTOU) Race Condition in Microsoft Edge - CVE-2026-58299

Vulnerability details

The vulnerability allows a remote attacker to execute arbitrary code.

The vulnerability exists due to a time-of-check time-of-use race condition in Microsoft Edge for Android autofill handling when processing attacker-controlled web content and crafted files. A remote attacker can craft deceptive or invisible form elements and induce the user to perform two sequential taps to execute arbitrary code.

User interaction is required: the user must visit an attacker-controlled webpage or open a specially crafted file, and the exploitation sequence requires two tap gestures that cause autofill to activate.

Affected software

How to mitigate CVE-2026-58299

External References

• https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2026-58299
• https://docs.microsoft.com/en-us/DeployEdge/microsoft-edge-relnotes-security

Related Security Bulletins

• Multiple vulnerabilities in Microsoft Edge