CVE-2025-14765: How Edge Gets the Chromium Patch via Microsoft SUG

Microsoft’s Security Update Guide now lists CVE-2025-14765 — an out‑of‑bounds read and write vulnerability in the V8 JavaScript engine used by Chromium — because Microsoft Edge (Chromium‑based) consumes upstream Chromium code and Microsoft publishes the Security Update Guide entry to show whether Edge builds have ingested the upstream fix and are no longer vulnerable.

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Background / Overview​

The V8 engine is the high‑performance JavaScript and WebAssembly runtime inside Chromium. It uses aggressive runtime optimizations and just‑in‑time compilation to achieve speed, and those optimizations rely on internal assumptions about object shapes and types. When those assumptions are violated — for example by a logic error or type confusion — the result can be an out‑of‑bounds read or write that reads or overwrites memory outside an allocated buffer. In modern browsers, such primitives are often the first step toward information disclosure, heap corruption, and, when chained with other flaws, arbitrary code execution.
Vulnerabilities reachable from a web page (network attack vector) are especially high‑risk because an attacker needs only to convince a user to visit a crafted page or render a malicious script to attempt exploitation. That low interaction requirement and the potential to escalate to code execution is why V8 bugs are treated with high urgency by browser vendors.

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Why a Chromium CVE appears in Microsoft’s Security Update Guide​

• Microsoft Edge is built on Chromium. Edge consumes upstream Chromium components (Blink, V8, etc., so a CVE assigned to Chromium can affect Microsoft‑shipped Edge until Microsoft ingests the upstream patch into Edge and ships a patched Edge build.
• The Microsoft Security Update Guide (SUG) exists to map CVEs to Microsoft‑shipped products and builds, telling enterprise administrators exactly whether the Edge build they run is still vulnerable or has received the ingestion. That downstream mapping removes guesswork for patch managers.
• A Chrome/Chromium fix upstream is the start of the remediation chain; the security benefit only reaches Edge users after Microsoft pulls, validates, tests, and ships an Edge update that contains the Chromium ingestion. The SUG entry is the authoritative downstream signal that the ingestion is complete.

Put simply: the SUG entry is not an admission that Microsoft authored the bug — it is a transparency and servicing record that answers, “Has Microsoft shipped an Edge build that contains the Chromium fix?”

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What “out‑of‑bounds read and write in V8” actually means​

• An out‑of‑bounds read lets code read memory past an allocated buffer boundary, which can reveal heap contents, pointers, or sensitive data such as tokens and cookies.
• An out‑of‑bounds write lets code overwrite memory outside its intended area, which can corrupt object metadata, control structures, or JIT code — and that corruption can be turned into powerful exploitation primitives.
• In V8, these primitives are dangerous because JIT‑compiled code and engine optimizations amplify the impact. Skilled exploit developers can chain information leaks and memory corruption into stable arbitrary read/write primitives and then use those to break sandboxes or execute native code.

Caveat: public vulnerability summaries often withhold low‑level exploit mechanics until patches have widely rolled out. Any statements about confirmed in‑the‑wild exploitation for CVE‑2025‑14765 should be verified against authoritative vendor telemetry (Google, Microsoft, or government advisories) because exploit status can change quickly and is sometimes deliberately withheld to reduce weaponization risk.

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How to see the version of your browser (quick, authoritative checks)​

The fastest and most reliable method to confirm whether your browser has the fix is to:

• Read the browser’s own version string (full build).
• Compare that exact build string against the Microsoft Security Update Guide entry for CVE‑2025‑14765 (the SUG lists the Edge build that contains the ingestion) or the upstream Chromium/Chrome release notes (the Chrome build that contains the upstream fix).

Microsoft Edge — desktop (Windows, macOS, Linux)​

• Open Microsoft Edge.
• Go to the About page: Menu (three dots) → Help and feedback → About Microsoft Edge, or enter edge://settings/help in the address bar. The About page shows the exact Edge version and triggers an update check. Relaunch if an update is installed.
• For the full metadata (including the underlying Chromium revision and V8 version), enter edge://version in the address bar. Copy the full string to compare against the SUG or release notes.

Google Chrome — desktop​

• Open Chrome.
• Use About Google Chrome: Menu → Help → About Google Chrome, or enter chrome://settings/help. This page shows the Chrome version and checks for updates. For full detail use chrome://version.

Mobile (Edge on Android / iOS)​

• Mobile builds are distributed through platform stores and may not always expose the exact Chromium revision. Use the app’s Settings → About or check the OS App Info / Play Store / App Store entry for the version string. Confirm mapping to the upstream fix using vendor advisories.

Embedded runtimes and Electron apps​

• Many desktop apps and appliances bundle their own Chromium/V8 runtime (Electron apps, kiosk UIs, WebView/WebView2). Those runtimes do not auto‑update with the browser. Check the app’s About box or vendor release notes for the bundled Chromium revision; the app is vulnerable until the vendor ships a rebuild that contains the patched Chromium.

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Mapping a version to “patched” — the authoritative sources and why to cross‑check​

• Upstream source: Chrome/Chromium release notes list the Chrome build(s) that contain the upstream fix. Use those to know the upstream remediation boundary.
• Downstream source: Microsoft’s Security Update Guide and Edge release notes list the Edge build(s) containing the ingestion. Use SUG as the downstream authority for Edge.

Best practice: always confirm remediation with at least two independent sources — the Chrome/Chromium release notes and Microsoft’s SUG (or Edge release notes). That avoids misinterpretation when release numbering or ingestion boundaries differ slightly between vendors.
Important operational note: a single Chrome patch upstream does not immediately mean every downstream Chromium consumer is protected. Edge is only safe once Microsoft ships the Edge build that includes the ingestion; other products (Brave, Opera, Vivaldi, Electron apps, embedded WebViews) must also ingest the fix independently. The SUG entry exists precisely to communicate that downstream ingestion status for Microsoft products.

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Practical remediation checklist (end‑user and enterprise)​

• For end users:
• Open Edge (or Chrome) → About page → Update and relaunch if updates are available. Confirm the version string matches or exceeds the patched build listed by your vendor.
• If you use many Electron apps (Slack, VS Code variants, Discord), check each app’s About page or vendor advisory for bundled Chromium updates.
• For administrators and security teams:
• Inventory all Chromium consumers: Edge (desktop/mobile), Electron applications, WebView/WebView2 instances, kiosk appliances, cloud rendering services, and server side headless browsers.
• Use automated software inventory and endpoint management (Intune, SCCM/ConfigMgr, EDR) to collect version strings from endpoints and flag any builds older than the SUG/Chrome fixed boundary.
• Apply updates centrally and require a browser relaunch to activate the patch.
• Where immediate ingestion is not possible (specialized appliances, long‑lived embedded devices), apply compensating controls: network filtering, content allowlists, tighter web proxy policies, or temporary substitution to a non‑Chromium browser for sensitive tasks.
• Tune EDR rules and crash monitoring to detect anomalous renderer crashes, unusual child process behavior, or post‑exploit indicators.
• Prioritize endpoints that handle sensitive data or have high‑privilege users.
• Track the SUG entry for CVE‑2025‑14765 and Microsoft Edge release notes for the ingestion build.
• Produce audit evidence showing pre‑ and post‑update build numbers for compliance and incident response.

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Incident response, detection, and what to watch for​

• Typical initial signs of exploitation:
• Frequent, reproducible renderer crashes in a cluster of users.
• Unexplained low‑level browser process instability or sudden increase in browser crashes correlated to specific sites.
• Suspicious child processes spawned by browsers or unusual network traffic following a crash.
• Detection tips:
• Monitor crash telemetry and correlate with browsing activity to identify whether crashes spike after visits to particular sites, ad networks, or content feeds.
• Use EDR to capture process memory or dump renderer processes for forensic analysis if exploitation is suspected.
• If vendor advisories confirm in‑the‑wild exploitation for CVE‑2025‑14765, raise priority to immediate emergency patching and hunt for possible compromise artifacts. (Verify exploitation claims against vendor telemetry before concluding an incident.

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Risk assessment — what makes this class of bug high priority​

• Remote reachability: the attacker only needs to deliver crafted HTML/JS — often achievable via a web page, malvertising, or a compromised site.
• Low interaction: visiting a page is low friction, and many successful exploits in the past required nothing more than a page load.
• Exploitation primitives: out‑of‑bounds reads/writes in V8 can be converted into reliable arbitrary read/write primitives and then into sandbox escapes. Historically, V8 memory‑safety bugs have been used in the wild.

Unverified claims warning: public reports sometimes conflate multiple V8 CVEs disclosed in the same Chrome promotion window. Confirm the exact CVE‑to‑build mapping for CVE‑2025‑14765 in the SUG and Chrome release notes before assuming exploit status or build boundaries. Treat any claim of active exploitation as provisional until corroborated by vendor telemetry or national advisories.

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Practical examples — checking and comparing versions (copy‑and‑paste steps)​

• Edge — desktop quick check:
• Open Edge → type edge://settings/help → note the version string (or edge://version for full metadata). Compare that string to the SUG entry for CVE‑2025‑14765.
• Chrome — desktop quick check:
• Open Chrome → type chrome://settings/help or chrome://version → note full build string and compare to the Chrome release notes for the CVE.
• Linux / automated collection:
• Use package manager queries (apt list --installed google-chrome-stable or google-chrome --version) and map the package version to upstream Chromium builds via vendor release notes.
• Enterprise reporting:
• Use endpoint management to gather edge://version output across the fleet, store the build strings in a central inventory, and automatically flag any host with a build older than the SUG‑listed remediation version.

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Supply‑chain nuance — downstream consumers beyond Edge​

Chromium and V8 are embedded widely: other browsers (Brave, Opera, Vivaldi), Electron‑based desktop apps, mobile WebViews, kiosk appliances, and headless rendering services. Each of these is a separate downstream consumer that must ingest the upstream fix. Enterprise risk arises when these consumers lag behind Chrome’s upstream patch because the application bundles a fixed Chromium/V8 runtime that is updated only when the vendor releases a new package. Inventorying all such runtimes is therefore critical to closing the exposure window.

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Final recommendations and takeaways​

• Why the CVE appears in SUG: Microsoft’s Security Update Guide lists CVE‑2025‑14765 to declare whether Microsoft Edge has ingested the upstream Chromium patch and is no longer vulnerable — it’s a downstream remediation status signal for administrators.
• How to confirm protection: check your exact browser build via edge://version (Edge) or chrome://version (Chrome) and compare that full build string to the Microsoft Security Update Guide entry for CVE‑2025‑14765 or the Chrome release notes.
• Immediate actions:
• Update and relaunch browsers across endpoints.
• Inventory all Chromium consumers and force updates or apply compensating controls where immediate updates are not possible.
• Monitor crash telemetry and EDR alerts for suspicious renderer crashes or post‑exploit behavior.
• Verification discipline: whenever possible, cross‑check the remediation boundary using both Chrome/Chromium release notes (upstream) and Microsoft’s Security Update Guide / Edge release notes (downstream) because ingestion timing and build boundaries may differ.

A well‑executed update and verification plan — checking exact build strings and confirming ingestion in the Security Update Guide — is the fastest way to move from uncertainty to assurance that your Edge fleet is no longer exposed to CVE‑2025‑14765.

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Conclusion: CVE‑2025‑14765 is a classic example of why downstream visibility matters in modern open‑source supply chains. Microsoft’s Security Update Guide entry is the operational signal administrators need: it tells you whether Edge has caught up with the upstream Chromium fix. Confirm protection by checking the browser’s About/Version page and matching the exact build string with the SUG/Chrome release notes, update promptly, and inventory all Chromium‑based runtimes in your environment to close the exposure window.

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Source: MSRC Security Update Guide - Microsoft Security Response Center