CVE-2026-10943: Use-After-Free in Chrome WebRTC – High Severity, Patch Now

Technical summary

CVE-2026-10943 is a use-after-free (CWE-416) vulnerability in the WebRTC implementation of Google Chrome prior to version 149.0.7827.53. Use-after-free flaws occur when code attempts to access memory that has already been freed, potentially allowing an attacker to corrupt heap data structures and execute arbitrary code. In this case, the vulnerability is triggered through a specially crafted HTML page delivered over the network (AV:N). No special privileges are required (PR:N), and the attack requires only user interaction such as visiting the malicious page (UI:R). The vulnerability affects Chrome on multiple operating systems including macOS, Linux, and Windows. While the code execution is constrained to the Chrome sandbox (S:U), the attacker achieves high impact across confidentiality, integrity, and availability (C:H/I:H/A:H).

Business impact

Organizations and individuals relying on Chrome as their primary browser face direct risk. An attacker exploiting this vulnerability could compromise user data, inject malware payloads, or disrupt browsing sessions. For enterprises, this could lead to credential theft, sensitive document exposure, or lateral movement if the compromised Chrome instance has access to internal network resources. The sandbox containment limits (but does not eliminate) risk of full system compromise, yet the high CVSS score reflects the severity of potential data exfiltration and system manipulation. Delayed patching increases the window of exposure.

Affected systems

Google Chrome versions prior to 149.0.7827.53 are vulnerable across multiple platforms: macOS, Linux, and Windows. Any user or system running an affected Chrome version and visiting a malicious website is at risk. This includes enterprise deployments where Chrome is a managed browser, as well as consumer users. Organizations should inventory Chrome deployments and prioritize updates, particularly for systems handling sensitive data or with network access to critical resources.

Exploitability

Exploitability is moderate to high. The attack requires network delivery of a crafted HTML page (typical via compromised website or targeted phishing) and user interaction (visiting the page). There is no requirement for social engineering beyond convincing a user to visit a link, making this a relatively low barrier to exploitation. The vulnerability does not require authentication or elevated privileges. However, the attack does depend on user action and browser availability, which are standard constraints. Given the Chromium severity rating of High and the network-accessible vector, security teams should assume active exploitation is probable once detailed information becomes widely available.

Remediation

Update Google Chrome to version 149.0.7827.53 or later. This patch addresses the use-after-free condition in WebRTC. Users should enable automatic updates if not already active, as Chrome typically updates itself in the background. For enterprise deployments, IT teams should test the patch in a controlled environment before rolling out organization-wide to ensure compatibility with internal applications and policies. Verify the patch installation by checking Chrome's About page (chrome://about/), which will display the installed version number.

Patch guidance

Deploy Chrome 149.0.7827.53 or later. For organizations using managed Chrome deployments (via enterprise policies), prioritize pushing this update through your Chrome Enterprise account or MDM/EMM solution. Verify that auto-update is enabled for user-installed Chrome instances. Test the patched version against mission-critical internal web applications before full rollout. Monitor for any compatibility issues and plan a phased rollout if needed, though the security risk argues for rapid deployment. Confirm successful patch application by verifying version numbers across your user base post-deployment.

Detection guidance

Monitor for suspicious WebRTC activity and malformed HTML pages in network traffic. Web content filtering and intrusion detection systems should flag pages attempting to trigger heap corruption in WebRTC streams. Check Chrome browser logs and crash reports for WebRTC-related segmentation faults or memory violations occurring shortly before exploitation attempts. Endpoint detection and response (EDR) tools should monitor for unusual process behavior spawned from Chrome, particularly after page loads. Examine user browsing history for visits to unusual or newly registered domains that might host exploit pages. Consider deploying network-based monitoring to detect command-and-control communication from potentially compromised browser sessions.

Why prioritize this

This vulnerability merits immediate prioritization due to its high CVSS score (8.8), network-accessible attack vector, low barrier to exploitation (user interaction only), and the ubiquity of Chrome as a browser. The sandbox containment, while providing some protection, does not eliminate risk—sandboxes have been escaped before, and data exfiltration from within a sandbox remains a serious concern. The lack of KEV status (not yet in CISA's known-exploited vulnerabilities catalog) does not diminish urgency; widespread exploitation is likely as technical details proliferate. Organizations should treat this as a tier-1 patch candidate.

Risk score, explained

The CVSS 3.1 score of 8.8 reflects high severity across multiple dimensions. The network-accessible attack vector (AV:N) and lack of privilege requirements (PR:N) mean any internet user is a potential target. User interaction is required (UI:R), which slightly lowers risk compared to fully automatic exploitation, but visiting a malicious page is a common occurrence. The high impact across confidentiality, integrity, and availability (C:H/I:H/A:H) acknowledges that once code execution is achieved in the sandbox, attackers can read sensitive browser data, inject content, or crash the browser. The scope is unchanged (S:U), meaning the vulnerability does not directly impact resources outside the Chrome process itself, though data theft from the browser is a form of confidentiality impact. The combination of ease of exploitation and significant impact justifies the high score.

Frequently asked questions