Chrome Patch Fixes Dawn WebGPU UAF CVE-2025-10500; Edge Ingestion Reminder

Google’s September stable update for Chrome closed a notable Use‑After‑Free (UAF) in the Dawn WebGPU implementation — tracked as CVE‑2025‑10500 — alongside several other high‑severity graphics and engine fixes; Windows users and administrators running Microsoft Edge (Chromium‑based) should treat this as a high‑priority ingestion and patching event because Edge inherits Chromium fixes only after downstream ingestion and testing. (intruceptlabs.com)

Background​

What Dawn and WebGPU are, and why they matter​

Dawn is the Native/Web implementation layer for WebGPU inside Chromium: it mediates web‑facing WebGPU calls to the underlying GPU APIs and drivers. WebGPU exposes a modern, low‑level graphics and compute API to web pages; because it reaches deeper into GPU resources than traditional WebGL, bugs in Dawn can be attractive to attackers and high impact when they occur. Past Dawn UAFs have produced heap corruption and, in chained exploits, remote code execution. (nvd.nist.gov)

What a use‑after‑free means in practice​

A use‑after‑free (CWE‑416) happens when program logic deallocates memory but later dereferences the stale pointer. In a multi‑component, multi‑process browser architecture, a UAF in a GPU mediation layer like Dawn can be triggered remotely by crafted web content. If an attacker can reliably control heap layout after the free (heap grooming), they can steer program behavior into executing attacker‑controlled data or otherwise corrupt critical process memory. Such corruption is commonly exploited to compromise the renderer process and, in sophisticated chains, to attempt sandbox escapes. (securityweek.com)

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The CVE and the patch: what was fixed​

The vulnerability in brief​

• Vulnerability: Use‑After‑Free in Dawn (Chromium’s WebGPU layer).
• Tracking ID: CVE‑2025‑10500.
• Reported by: public reporting attributes the Dawn report to a named researcher and places the report in August 2025; Chromium assigned the CVE and rolled the fix into the stable branch. (cyberinsider.com)

Fixed Chrome versions (stable desktop)​

Google included the fix in the stable desktop update series that rolled Chrome to:

• 140.0.7339.185 (Linux) and
• 140.0.7339.185 / .186 (Windows and macOS).
  The September 2025 Stable channel update patched CVE‑2025‑10500 together with a separate V8 zero‑day and other graphics issues. Administrators should treat any Chrome build earlier than those listed as vulnerable until updated. (tenable.com)

Cross‑vendor note: why Microsoft Edge admins must care​

Because Microsoft Edge (Chromium‑based) tracks upstream Chromium, Edge is affected by the same underlying Dawn defect until Microsoft ingests and ships the patched Chromium components in downstream Edge builds. Microsoft publicly records Chromium‑assigned CVEs in its Security Update Guide and updates Edge downstream; organizations should confirm their Edge build includes the Chromium 140.x ingestion corresponding to the Chrome fix. Treat the Chrome version boundary as the upstream remediation baseline and verify Edge ingestion before deeming systems patched. (tenable.com)

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Technical analysis: attack surface, exploitability, and risk​

Why Dawn UAFs are high‑value targets​

Dawn bridges web content and GPU drivers. The graphics stack is complex and platform‑dependent: small mistakes in resource lifetime or command sequencing can free an object while other references still exist, producing a UAF. Because GPU drivers and their interfaces sit close to the OS and hardware, corrupting GPU‑related memory can provide powerful primitives for an attacker — it increases the attacker’s ability to manipulate memory layout and sometimes helps chain to sandbox bypasses. Historically, similar classes of renderer and GPU bugs have been weaponized in targeted attacks. (securityweek.com)

Exploitability and presence in the wild​

At the time of the Chrome stable rollout, reporting singled out a V8 type‑confusion zero‑day (CVE‑2025‑10585) as actively exploited. Public reports about CVE‑2025‑10500, the Dawn UAF, do not indicate active exploitation in the wild at the time of disclosure; Google withheld low‑level technical details to limit weaponization while the update deployed. That difference matters operationally but does not reduce urgency — any high‑severity memory‑corruption bug reachable from web content is a potential exploitation vector and should be patched immediately. Flag this statement as time‑sensitive: exploit telemetry can change rapidly, so reassess with threat‑intelligence feeds if you maintain fleets. (securityweek.com)

Difficulties for reliable exploitation​

While UAFs are a common primitive, reliable exploitation typically requires:

• Precise heap grooming and knowledge of allocator behavior on the target platform.
• Overcoming mitigations such as ASLR (Address Space Layout Randomization), CFI, and process sandboxes.
• Often chaining with other bugs to transit from renderer compromise to broader system control.

These hurdles mean a fully automated, wide‑scale exploit is rarer than simple proof‑of‑concepts — however, skilled threat actors and commercial spyware vendors have repeatedly used similar primitives against high‑value targets. Assume risk until patched. (securityweek.com)

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Who and what is affected​

Affected products and versions​

• Google Chrome builds prior to Chrome 140.0.7339.185/.186 (per platform) are affected. Update to the listed stable versions or later. (tenable.com)
• All Chromium‑based browsers (Microsoft Edge, Brave, Opera, Vivaldi, and embedded Chromium forks) that have not yet ingested Chromium’s 140.x security updates remain vulnerable until they ship equivalent patches. Enterprise fleets using vendor‑maintained browsers must coordinate with each vendor’s patch calendar. (intruceptlabs.com)

Risk profile by user group​

• Home users: Urgent but straightforward — update Chrome or Edge as delivered by the browser’s update mechanism.
• Enterprises and managed fleets: High priority for patching windows and test validation; verify Edge ingestion and coordinate rollouts to avoid gaps in protection.
• High‑value users (executives, IT administrators, developers): Increase attention; targeted attacks often favor users who combine web sessions with higher privileges.

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Recommended mitigations and operational steps​

Immediate actions for all users​

• Update Google Chrome to the latest stable release via Settings → Help → About Google Chrome, then restart the browser to apply patches. (intruceptlabs.com)
• If you run Microsoft Edge, verify the Edge version (edge://settings/help) and apply Edge updates as Microsoft releases them. Enterprise-installed Edge may also be updated via Windows Update, Microsoft Endpoint Manager / Intune, or your managed software distribution system. (support.microsoft.com)

Enterprise checklist (recommended)​

• Inventory: Identify all endpoints and servers running Chrome or Chromium‑based browsers.
• Version mapping: Match installed browser builds to Chromium upstream versions and mark any earlier than Chrome 140.0.7339.185/.186 as vulnerable.
• Apply updates: Deploy vendor updates (Chrome stable or ingested Edge stable patched builds) through your patch management pipeline and require restarts.
• Test: Validate critical web apps against the new browser build in a staged pilot before broad rollout.
• Monitor: Watch EDR, web proxy logs, and SIEM for indicators of compromise (sudden abnormal renderer crashes, unusual child‑process spawns, or dropped GPU process anomalies).
• Harden policies: Ensure automatic updates are enabled where acceptable and that update lag is minimized for high‑risk endpoints. (tenable.com)

Temporary mitigations (if you cannot patch immediately)​

• Disable or limit WebGPU exposure for high‑risk groups: WebGPU can be toggled via chrome://flags controls (search for “WebGPU” or “Unsafe WebGPU support”). Disabling the experimental WebGPU flags prevents web content from triggering Dawn code paths on some configurations, but be aware these flags are development features and behavior varies by platform. This is a stop‑gap, not a replacement for patching. (developer.chrome.com)
• Isolation: Enforce stricter browsing isolation for privileged accounts (use dedicated hardened browsing profiles or different browsers for sensitive tasks). Restrict opening untrusted links in the default browser.
• Network controls: Apply proxy or gateway web content filtering for high‑risk users and consider blocking known malicious domains.

Caveat: toggling chrome://flags or launching with non‑standard command‑line flags can produce unsupported behavior and may break legitimate apps relying on WebGPU. Use with caution and test before broad deployment. (developer.chrome.com)

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Detection and hunting guidance​

What to look for in logs and telemetry​

• Frequent or reproducible GPU process crashes or renderer process crashes tied to specific web origins.
• Unusual child processes or command‑line activity spawned from browser processes.
• Alerts from EDR for memory corruption patterns in browser processes or suspicious heap allocations.

Example SIEM/EDR hunting signals​

• Process creation events where the parent is chrome.exe or msedge.exe and the child is a suspicious binary.
• Renderer crash reports with crash stacks referencing WebGPU, Dawn, or GPU process modules.
• Sudden increases in blocked access attempts to known exploit infrastructure.

If specific PoCs or exploit indicators are published later, incorporate them into detection signatures and share via your threat‑intelligence feeds. When vendors publish public IOCs, adjust rules accordingly.

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Why vendors sometimes withhold technical details​

Browser vendors commonly restrict low‑level exploit details until a majority of users can update. That responsible disclosure practice reduces the window where widely shared technical details could be weaponized against unpatched clients. Still, defenders should assume adversaries will attempt to weaponize similar primitives and should act promptly on patches. (intruceptlabs.com)

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Historical context: Dawn has been patched before​

Dawn and the broader GPU/WebGPU surface have seen similar use‑after‑free bugs in the recent past; official advisories and NVD entries record multiple Dawn UAFs in 2024 and 2025. Those historical precedents emphasize the need for early and thorough patching and for continued attention to GPU‑mediated browser attack paths. This CVE continues that pattern. (nvd.nist.gov)

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Practical Q&A for administrators​

Q: How quickly should I patch?​

A: Immediately for high‑value and internet‑facing endpoints. For large enterprise rollouts, prioritize pilot groups and deploy to high‑risk user groups first, then accelerate the full rollout. Treat the Chrome 140.0.7339.185/.186 boundary as the upstream remediation target until your Edge builds confirm ingestion. (tenable.com)

Q: Can I rely on Microsoft to have Edge patched now?​

A: Microsoft typically ingests Chromium security fixes rapidly, but there is a downstream ingestion and testing window. Verify the specific Edge build (edge://settings/help) and consult Microsoft’s Security Update Guide for the CVE entry to confirm ingestion and the Edge build that includes the Chromium patch. Do not assume automatic parity without verification. (msrc.microsoft.com)

Q: If I disable WebGPU, am I safe?​

A: Disabling WebGPU reduces exposure to Dawn code paths but is not a guaranteed full mitigation — other components (WebRTC, ANGLE, V8) in the same update set had distinct vulnerabilities. The safest, long‑term action is to apply vendor patches. Use flag toggles only as an emergency stop‑gap and test for compatibility impacts. (developer.chrome.com)

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Closing analysis and risk assessment​

CVE‑2025‑10500 is a classic example of why modern browsers’ GPU stacks require continuous scrutiny: the combination of a deep hardware interface (WebGPU/Dawn) and web‑reachable APIs increases attack surface. Although at disclosure priority was given to a separate actively‑exploited V8 zero‑day, the Dawn use‑after‑free is still a high‑severity memory‑corruption bug that attackers can attempt to weaponize.
Strengths in the response:

• Google released a prompt stable‑channel update for Chrome and withheld exploit detail to limit abuse; public reporting has been consistent about remediation versions. (intruceptlabs.com)

Risks and operational concerns:

• Microsoft Edge and other Chromium forks remain vulnerable until they ingest and ship the patched Chromium components; enterprises must verify ingestion and not assume immediate parity. (tenable.com)
• Exploit disclosures are a moving target — lack of reported in‑the‑wild exploitation for CVE‑2025‑10500 is not proof of safety. Maintain vigilant patching and detection posture. (securityweek.com)

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Final checklist (copy‑paste for ops)​

• Check browser versions:
• Chrome: open Settings → Help → About Google Chrome; confirm version ≥ 140.0.7339.185/.186. (intruceptlabs.com)
• Edge: open edge://settings/help; confirm the Edge build includes Chromium 140.x ingestion. (support.microsoft.com)
• If vulnerable, schedule immediate updates and restarts.
• For managed fleets, push the patched package via your patch management system and require restarts.
• If you must delay, consider disabling WebGPU for sensitive accounts (test first) and tighten network/web gateway controls.
• Monitor crash telemetry, EDR alerts for browser process anomalies, and SIEM for suspicious activity.

CVE‑2025‑10500 is an urgent reminder that graphics layers are a high‑value frontier in browser security. Apply the available updates, confirm downstream ingestion into Edge if you manage Microsoft fleets, and close the window of exposure as quickly as your change control permits. (intruceptlabs.com)

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Source: MSRC Security Update Guide - Microsoft Security Response Center