CVE-2026-55945 in Edge
Summary
by MITRE • 07/04/2026
Concurrent execution using shared resource with improper synchronization ('race condition') in Microsoft Edge (Chromium-based) allows an authorized attacker to disclose information locally.
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Analysis
by VulDB Data Team • 07/04/2026
This vulnerability represents a classic race condition flaw that exploits concurrent execution patterns within Microsoft Edge's Chromium-based architecture. The issue manifests when multiple threads or processes attempt to access shared resources simultaneously without proper synchronization mechanisms, creating opportunities for unauthorized information disclosure. The vulnerability specifically affects the browser's handling of shared memory segments and resource management during concurrent operations, allowing an attacker with local system access to potentially extract sensitive data through carefully timed execution sequences.
The technical implementation of this race condition occurs at the kernel or system level where Edge's Chromium engine manages shared resources across different execution contexts. When multiple processes or threads attempt to read from or write to the same memory location or resource simultaneously, the lack of proper locking mechanisms or atomic operations creates windows of opportunity for data leakage. This type of vulnerability is classified under CWE-362 which specifically addresses race conditions in concurrent programming environments where insufficient synchronization leads to unpredictable behavior and potential security breaches.
From an operational perspective, this vulnerability presents significant risk to organizations as it requires only local system access to exploit, making it particularly dangerous in environments where users may have elevated privileges or where privilege escalation occurs through other attack vectors. The information disclosure aspect could potentially expose sensitive user data, session tokens, or system credentials that are stored in shared memory regions during browser operations. Attackers can leverage this weakness by creating race conditions through carefully crafted JavaScript code or system-level processes that manipulate timing and access patterns to extract confidential information from memory segments.
The attack vector typically involves an authorized user or process executing malicious code within the browser environment that takes advantage of the timing window between resource allocation and synchronization checks. According to ATT&CK framework, this represents a technique under T1059.007 for Command and Scripting Interpreter with focus on JavaScript execution, and potentially falls under T1068 for Exploitation for Privilege Escalation when combined with other attack methods. The vulnerability's impact extends beyond simple information disclosure as it can serve as a foundation for more sophisticated attacks including credential theft or further privilege escalation within the compromised system.
Mitigation strategies should focus on implementing proper synchronization mechanisms throughout the browser's codebase, including mutex locks, semaphores, and atomic operations to prevent concurrent access to shared resources. System administrators should ensure that Microsoft Edge is kept up-to-date with the latest security patches and updates from Microsoft. Additional protective measures include deploying application whitelisting solutions, implementing strict browser security policies, and monitoring for unusual process behavior or memory access patterns that might indicate exploitation attempts. Organizations should also consider network segmentation and privilege separation to limit potential damage if such vulnerabilities are successfully exploited in real-world scenarios.