CVE-2026-5864 Overview
CVE-2026-5864 is a heap buffer overflow vulnerability in the WebAudio component of Google Chrome prior to version 147.0.7727.55. A remote attacker can craft a malicious HTML page that triggers an out-of-bounds memory read in the renderer process. Successful exploitation allows the attacker to obtain potentially sensitive information from Chrome process memory. The flaw is tracked under [CWE-122: Heap-based Buffer Overflow] and affects Chrome installations across Windows, macOS, and Linux. Chromium classified the issue with an internal severity of High, though the NVD CVSS rating reflects the information-disclosure scope of impact.
Critical Impact
Remote attackers can leak sensitive data from Chrome process memory by luring users to a crafted web page rendered by the WebAudio subsystem.
Affected Products
- Google Chrome prior to 147.0.7727.55
- Chromium-based browsers on Microsoft Windows, Apple macOS, and Linux
- Embedded applications using Chromium WebAudio components
Discovery Timeline
- 2026-04-08 - CVE-2026-5864 published to NVD
- 2026-04-14 - Last updated in NVD database
Technical Details for CVE-2026-5864
Vulnerability Analysis
The vulnerability resides in the WebAudio implementation within Chrome's renderer process. WebAudio handles digital audio processing through the Web Audio API, including buffer allocation, mixing, and signal graph operations. A heap-based buffer overflow in this code path lets attacker-controlled content read beyond the bounds of an allocated heap region. The exploitation primitive in this case yields information disclosure rather than code execution, exposing adjacent heap memory contents to JavaScript running on a crafted page. Leaked data may include pointers useful for bypassing Address Space Layout Randomization (ASLR) or fragments of in-process data from other browsing contexts. User interaction is required: a victim must load or navigate to a malicious HTML page.
Root Cause
The root cause is improper bounds enforcement on a heap buffer during WebAudio processing. The defect maps to [CWE-122], where the size of data written or read from a heap allocation is not properly validated against the allocation length. Technical specifics are tracked in Chromium Issue Tracker #490642831.
Attack Vector
Exploitation occurs over the network through standard web content delivery. An attacker hosts a crafted HTML page that invokes the WebAudio API with parameters designed to trigger the out-of-bounds access. When a victim visits the page using a vulnerable Chrome build, the renderer process exposes heap memory to the attacker's JavaScript. No authentication is required, and the attack scales trivially through phishing, malvertising, or compromised third-party content.
No public proof-of-concept or in-the-wild exploitation has been documented at the time of publication. Refer to the Google Chrome Security Update and the Chromium Issue Tracker #490642831 for vendor-supplied technical detail.
Detection Methods for CVE-2026-5864
Indicators of Compromise
- Chrome renderer process crashes or unexpected SIGSEGV events tied to WebAudio call stacks
- Outbound connections from end-user hosts to recently registered or low-reputation domains serving HTML with heavy WebAudio API usage
- Browser telemetry showing repeated AudioBuffer, AudioContext, or OfflineAudioContext operations from untrusted origins
Detection Strategies
- Inventory installed Chrome versions across the fleet and flag any build below 147.0.7727.55
- Correlate web proxy logs with threat intelligence feeds to identify access to malicious pages targeting Chromium audio components
- Monitor endpoint telemetry for anomalous child processes or crash dumps originating from chrome.exe renderer instances
Monitoring Recommendations
- Centralize browser version reporting through enterprise management tooling such as Chrome Browser Cloud Management
- Ingest browser crash and stability telemetry into the SIEM for trend analysis
- Alert on user reports of repeated Chrome tab crashes after visiting external sites
How to Mitigate CVE-2026-5864
Immediate Actions Required
- Update Google Chrome to version 147.0.7727.55 or later on all Windows, macOS, and Linux endpoints
- Force-restart Chrome processes after the update so the patched binaries are loaded
- Audit Chromium-based applications and embedded WebViews for upstream patch adoption
Patch Information
Google released the fix in the Stable Channel update documented in the Google Chrome Security Update. Administrators should deploy 147.0.7727.55 or later through standard enterprise update mechanisms. Chromium downstream vendors should track the fix referenced in Chromium Issue Tracker #490642831 and rebase accordingly.
Workarounds
- Restrict access to untrusted websites through web filtering or DNS-layer controls until patching completes
- Disable or restrict the Web Audio API via enterprise browser policy where business workflows permit
- Enable Site Isolation and Enhanced Safe Browsing to reduce the impact of renderer-level memory disclosure
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
