Google Chrome Dawn WebGPU Use-After-Free Zero-Day Under Active Exploitation (CVE-2026-5281)

Google Chrome Dawn WebGPU Use-After-Free Zero-Day Under (TL-2026-0321), also tracked as Chrome Dawn Zero-Day, is a critical-severity zero-day vulnerability scored CVSS 8.8, first published 2026-04-06. It has no confirmed attribution, affects Google Chrome, references 1 CVE (CVE-2026-5281), maps to 14 MITRE ATT&CK techniques (T1005, T1036, T1041), and is covered by 9 detection rules and 15 indicators of compromise.

Key facts for TL-2026-0321

Threat ID
TL-2026-0321
Also known as
Chrome Dawn Zero-Day, WebGPU UAF
Severity
CRITICAL
CVSS
8.8 (CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H)
Status
PATCHED
Category
ZERO_DAY
First published
2026-04-06
Last reviewed
2026-04-06
Attribution confidence
NONE
Motivation
UNKNOWN
Target sectors
government, financial, technology, defense, critical-infrastructure, healthcare, education, energy
Target regions
Global
Detection rules
9
Indicators of compromise
15

Malware and tooling in Google Chrome Dawn WebGPU Use-After-Free Zero-Day Under

Malware and tooling: WebGPU exploitation framework (unnamed/unreleased)

A use-after-free vulnerability (CWE-416) in Dawn, Chromium's WebGPU implementation, allows a remote attacker who has compromised the renderer process to execute arbitrary code and potentially escape the browser sandbox via a crafted HTML page. Actively exploited in the wild and added to the CISA KEV catalog on April 1, 2026 with a remediation deadline of April 15, 2026. This is the fourth actively exploited Chrome zero-day of 2026.

How Google Chrome Dawn WebGPU Use-After-Free Zero-Day Under works

CVE-2026-5281 is a critical use-after-free (UAF) memory safety vulnerability in Dawn, Google's open-source cross-platform implementation of the WebGPU standard that serves as the abstraction layer between web applications calling WebGPU APIs and GPU hardware. Dawn translates graphics and compute instructions into platform-specific GPU calls: Vulkan on Linux, Metal on macOS, and Direct3D 12 on Windows.

The vulnerability stems from Dawn's object lifetime management pattern. The component relies on raw pointers to reference-counted objects while assuming external lifetime guarantees. As documented in Chromium's WebGPU research, WebGPU objects have lifetimes that span multiple layers of reference counting and raw pointers, creating conditions where stale pointers can persist. This manifests when objects are freed but references remain in queues (such as pending sets), and asynchronous execution occurs before later code accesses the freed memory, violating lifetime assumptions.

The exploit chain operates in a two-stage model. In stage one, an attacker must first compromise Chrome's renderer process through a separate vulnerability. In stage two, a crafted HTML page triggers the Dawn use-after-free, allowing the attacker to fill freed memory space with malicious code. The result is arbitrary code execution in the GPU process context, which runs at a higher privilege level than the sandboxed renderer process. This effectively provides a sandbox escape primitive, as Dawn provides a boundary-crossing path from the renderer process (sandboxed, untrusted) through the WebGPU API, Dawn Wire, and GPU process command buffer to Dawn Native and native graphics APIs.

Chromium's severity guidance classifies this vulnerability as high-severity because it bypasses sandbox boundaries, despite requiring prior renderer compromise. The vulnerability was reported by a pseudonymous researcher identified as _86ac1f1587b71893ed2ad792cd7dde32_, who had previously identified CVE-2026-4675 (heap buffer overflow in WebGL) and CVE-2026-4676 (another UAF in Dawn), both fixed on March 23, 2026. Additional Dawn use-after-free flaws CVE-2026-5284 and CVE-2026-5286 were patched in the same release.

Google confirmed active in-the-wild exploitation on March 31, 2026, and CISA added CVE-2026-5281 to the Known Exploited Vulnerabilities catalog on April 1, 2026, requiring Federal Civilian Executive Branch agencies to remediate by April 15, 2026. This represents the fourth actively exploited Chrome zero-day of 2026, following CVE-2026-2441 (CSS engine UAF, February), CVE-2026-3909 (Skia out-of-bounds write, March), and CVE-2026-3910 (V8 JavaScript engine flaw, March). The accelerating cadence of browser zero-days targeting graphics subsystems underscores that WebGPU remains premium attack surface due to performance demands, cross-platform complexity, and native code dependencies.

The release that patched CVE-2026-5281 addressed 21 total security fixes including memory safety issues across WebGL, WebCodecs, CSS, ANGLE, WebUSB, Web MIDI, V8, PDF handling, Navigation, and Compositing components. All Chromium-based browsers including Microsoft Edge, Brave, Opera, and Vivaldi are affected until they incorporate the upstream fixes.

MITRE ATT&CK techniques used in TL-2026-0321

collection

T1005 Data from Local System

defense-evasion

T1036 Masquerading; T1055 Process Injection; T1211 Exploitation for Stealth

exfiltration

T1041 Exfiltration Over C2 Channel

discovery

T1057 Process Discovery; T1082 System Information Discovery

execution

T1059 Command and Scripting Interpreter; T1203 Exploitation for Client Execution

privilege-escalation

T1068 Exploitation for Privilege Escalation

command-and-control

T1071 Application Layer Protocol

initial-access

T1189 Drive-by Compromise

impact

T1499 Endpoint Denial of Service

resource-development

T1587 Develop Capabilities

Affected products and versions in Google Chrome Dawn WebGPU Use-After-Free Zero-Day Under

  • Google — Chrome
    Vulnerable versions: < 146.0.7680.177 (Linux); < 146.0.7680.178 (Windows); < 146.0.7680.178 (macOS)
    Fixed in: 146.0.7680.177 (Linux); 146.0.7680.177/178 (Windows); 146.0.7680.177/178 (macOS)
  • Microsoft — Edge
    Vulnerable versions: < 146.0.3856.97
    Fixed in: 146.0.3856.97+
  • Vivaldi — Vivaldi Browser
    Vulnerable versions: Versions prior to April 2026 patch
    Fixed in: Patched build released April 2026
  • Brave — Brave Browser
    Vulnerable versions: Chromium < 146.0.7680.177
    Fixed in: Chromium 146.0.7680.177+
  • Opera — Opera Browser
    Vulnerable versions: Chromium < 146.0.7680.177
    Fixed in: Chromium 146.0.7680.177+

Remediation for Google Chrome Dawn WebGPU Use-After-Free Zero-Day Under

Patches

  • Google Chrome 146.0.7680.177/178 (Windows/macOS) — released March 31, 2026
  • Google Chrome 146.0.7680.177 (Linux) — released March 31, 2026
  • Microsoft Edge 146.0.3856.97 (Stable) — released April 2026
  • Vivaldi — fix deployed as of April 2026

Immediate actions

  • Force Chrome update to version 146.0.7680.177/178 (Windows/macOS) or 146.0.7680.177 (Linux) across all endpoints immediately
  • Verify running browser processes match the patched build number using chrome://version
  • Prioritize patching for internet-facing users and privileged accounts
  • Update Microsoft Edge to 146.0.3856.97 or later
  • Verify all other Chromium-based browsers (Brave, Opera, Vivaldi) have incorporated upstream fixes

Workarounds

  • Disable WebGPU via Chrome enterprise policy (--disable-features=WebGPU) on endpoints where GPU acceleration is not required
  • Restrict access to untrusted web content through web filtering proxies
  • Monitor for unusual GPU process crashes via crash reporting telemetry
  • Preserve crash artifacts and EDR timelines on systems that have not yet been patched

Longer-term hardening

  • Deploy EDR/XDR with behavioral detection and browser exploit mitigation capabilities
  • Implement browser isolation solutions for high-risk users
  • Enable Chrome enterprise policies to restrict WebGPU and WebGL on non-essential endpoints
  • Establish automated browser version compliance monitoring
  • Implement network segmentation to limit post-exploitation lateral movement
  • Deploy DNS filtering and web content filtering to block known malicious domains

CVEs associated with Google Chrome Dawn WebGPU Use-After-Free Zero-Day Under

CVE-2026-5281

Weaknesses (CWE) in Google Chrome Dawn WebGPU Use-After-Free Zero-Day Under

CWE-416

Timeline of Google Chrome Dawn WebGPU Use-After-Free Zero-Day Under

  • Google patches CVE-2026-4675 (heap buffer overflow in WebGL) and CVE-2026-4676 (UAF in Dawn), both reported by the same pseudonymous researcher _86ac1f1587b71893ed2ad792cd7dde32_ who later reported CVE-2026-5281
  • Google publicly acknowledges active in-the-wild exploitation of CVE-2026-5281 in the Chrome Stable Channel update blog post
  • Google releases Chrome Stable Channel Update 146.0.7680.177/178 for Windows/macOS and 146.0.7680.177 for Linux, fixing CVE-2026-5281 along with 20 additional security vulnerabilities. Google confirms an exploit for CVE-2026-5281 exists in the wild
  • Cyber Security Agency of Singapore (CSA) issues advisory AL-2026-029 warning of active exploitation. Qualys releases detection QIDs 386954 and 386965. Multiple security vendors publish analysis and detection guidance
  • NVD publishes CVE-2026-5281 with CVSS v3.1 base score of 8.8 (HIGH), vector CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H, and CWE-416 classification
  • CISA adds CVE-2026-5281 to the Known Exploited Vulnerabilities (KEV) catalog, requiring Federal Civilian Executive Branch agencies to apply remediation by April 15, 2026
  • Microsoft Edge releases version 146.0.3856.97 incorporating the upstream Chromium fix for CVE-2026-5281. Vivaldi also deploys a patched build
  • CISA KEV remediation deadline for Federal Civilian Executive Branch agencies per BOD 22-01
  • As of 2026-05-29, CVE-2026-5281 (Chrome Dawn WebGPU UAF) is patched in Chrome 146.0.7680.177/178 and downstream Chromium browsers, with the April 15 CISA KEV deadline now past and no exploitation reporting since early April. It remains exploitable only on unpatched legacy builds; the flaw is unattributed with no persistent actor or tooling to track.

Sources cited for Google Chrome Dawn WebGPU Use-After-Free Zero-Day Under

Threats related to Google Chrome Dawn WebGPU Use-After-Free Zero-Day Under

Detection coverage for TL-2026-0321

As of 2026-04-06, Threadlinqs Intelligence publishes 9 detection rule(s) for TL-2026-0321 across Splunk SPL, Microsoft KQL and Sigma, covering 15 indicator(s) of compromise. The whole corpus is readable without an account; a free account unlocks full detection query text in Splunk SPL, Microsoft KQL and Sigma; paid tiers add raw indicator values, correlation and the MCP server. Threadlinqs MCP server · View plans.

Threadlinqs Intelligence — Real-Time Threat Detection Platform

[ 0 threats ] [ 0 det ] [ CRIT: 0 ] [ HIGH: 0 ]
// threat_feed
$ sort --newest
Showing all threats

Latest Threats