Edge for Android UI Spoofing: Patch Now for Network Attacks (CVE-2025-49755)

Microsoft’s security advisory around a freshly disclosed browser bug highlights a repeat problem for mobile users: an insufficient UI warning in Microsoft Edge (Chromium-based) for Android that enables spoofing over a network. The vendor entry you provided points to a CVE record that the Microsoft Security Response Center exposes through its interactive Security Update Guide, but public aggregator listings and third‑party trackers show multiple closely related Edge mobile spoofing CVEs published in 2025, with patch guidance tied to the Android Edge release family—so the safest immediate action is to treat the issue as patch now critical for mobile fleets and personal devices. (nvd.nist.gov)

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Background / Overview​

Mobile browsers are a frequent target for UI‑spoofing and UI misrepresentation vulnerabilities because of limited screen real estate, condensed chrome, and interaction patterns (single‑tap decisions and in‑app link opening) that make spoofing particularly effective. Microsoft has tracked this class of problems using CWE‑451 (User Interface Misrepresentation of Critical Information) and related descriptors such as “the UI performs the wrong action.” Recent advisories for Microsoft Edge on Android describe the vulnerability as an insufficient UI warning of dangerous operations that allows an attacker—remotely, over the network—to present misleading UI and thereby trick users into revealing credentials, authorizing actions, or downloading content. (nvd.nist.gov)
Public trackers and vulnerability databases list multiple related CVEs for Edge’s mobile builds in 2025 (for example, CVE‑2025‑49736 and CVE‑2025‑49755, both described as UI misrepresentation / spoofing for Edge on Android) and consistently identify the exploit vector as network—meaning malicious web content or links are sufficient to trigger attack scenarios. Those sources report vendor fixes rolled into specific Edge Android builds (see the patching guidance below). (cybersecurity-help.cz)
Caveat on the CVE identifier: the MSRC page you linked renders via a JavaScript web app that may not expose the full metadata to non‑JS scrapers; public aggregators show adjacent CVE numbers for Edge Android spoofing published in August 2025. The discrepancy between the CVE in your link and widely indexed mirrors could be a transient rendering issue or a small typographical difference; the core risk (UI spoofing in Edge for Android) is corroborated across independent sources. Treat any specific numeric claim about the exact CVE or fixed build as verified only after checking MSRC directly or Microsoft’s release notes because interactive vendor pages sometimes hide details until patched builds appear in release channels. (nvd.nist.gov)

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What the vulnerability is and why it matters​

The technical gist​

• The defect is a UI misrepresentation / UI performs the wrong action class bug (CWE‑451/CWE‑449). It arises when the browser’s displayed controls or origin indicators (address bar, padlock, buttons, dialogs) become visually decoupled from the actual document or action target.
• On mobile, attackers can host crafted pages or deliver specially crafted links that manipulate navigation, overlays, timing, or frame composition so the user sees trusted chrome while interacting with attacker‑controlled content.
• The exploit does not require local privileges and is typically exploitable over the network, though it normally requires user interaction—a tap, a form submission, or acceptance of a UI element. (nvd.nist.gov)

Why mobile browsers are especially vulnerable​

Mobile viewports hide many visual cues users rely on to validate authenticity. The address bar and origin indicators occupy far less space, and browser chrome is commonly minimized or folded into gestures. Attackers exploit that tight screen space and habitual behavior (tap-first, read‑later) to make spoofed login prompts or fake download confirmations appear legitimate. Mobile in‑app browsers (link previews inside social apps) and one‑tap link opening increase the attack surface because users may not be in the full, updated browser context when they interact with the content.

Real‑world impact scenarios​

• Credential harvesting via a fake signin screen that appears to be from a bank or service provider because the address bar or padlock is spoofed.
• Unintentional permissions or downloads: a convincing, browser‑looking dialog prompts the user to install an APK or accept a download; the user taps, and the action proceeds.
• Second‑stage attacks: stolen credentials or granted permissions are leveraged to escalate into account takeover, fraudulent transactions, or targeted phishing.

These are social‑engineering‑first attacks; they don’t give immediate arbitrary code execution but often succeed because users are the easier target than hardened memory protections. Patch and behavioral defenses remain the primary mitigations. (feedly.com)

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Verified technical details and patch status​

Multiple independent vulnerability trackers that index vendor advisories and NVD records corroborate the core facts:

• Affected product: Microsoft Edge (Chromium‑based) for Android. (nvd.nist.gov)
• Exploit vector: Network (remote attacker‑hosted web content). (nvd.nist.gov)
• Typical CVSS / severity reported by aggregators: Medium (examples show CVSS v3.1 base scores in the 4.3–5.3 range depending on the exact CVE and how CVSS components were interpreted). These scores reflect network exploitability but required user interaction and limited confidentiality/integrity impact. (wiz.io)
• Fix guidance reported by public trackers: update Microsoft Edge for Android to the patched build(s). Several aggregators list 139.0.3405.86 (or later) as the remedial minimum for the Android channel where applicable. That build string appears repeatedly in independent trackers for closely related Edge Android spoofing CVEs. However, always confirm the fixed build number on Microsoft’s Security Update Guide before mass rollout. (cybersecurity-help.cz)

Important verification note: the Microsoft Security Response Center (MSRC) entry is authoritative and should be consulted for the final “fixed in” version and mitigation details, but the MSRC web page requires JavaScript to display full content; public scraping can return only the JS shell. Because of that rendering behavior, third‑party mirrors are currently used to corroborate facts, but confirm directly with MSRC in a browser (or use the Microsoft Security Update Guide APIs) before making absolute claims about exact build numbers.

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Analysis: strengths, weaknesses, and exploitation feasibility​

Strengths (from an attacker’s perspective)​

• Low technical complexity: UI spoofing is often easier to weaponize than memory‑corruption bugs because it relies on layout and user interaction control rather than bypassing platform mitigations.
• Scalable distribution: attack pages can be hosted on any web server or embedded in ads and shared via SMS, social platforms, or email.
• Human factors: mobile users habitually accept prompts or tap links quickly, making social engineering highly effective.

Harder parts / limiting factors for attackers​

• Requires user interaction: most public assessments note that a user must still tap or engage with the spoofed UI for the attack to succeed, which reduces automation of exploitation.
• Vendor patches and detection: once fixed in Chromium upstream or Microsoft Edge, signature‑based detections and hardened chrome‑binding reduce the attack feasibility on updated clients.
• Variability across devices: different Android OEMs, OS versions, and in‑app browser contexts may affect exploit reliability.

Overall feasibility: moderate. The vulnerability is valuable for phishing and credential theft campaigns because attackers need only social engineering and hosting; but broad, stealthy mass exploitation requires high‑quality spoofing and distribution channels. (wiz.io)

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Practical mitigation steps — immediate to 48 hours (for consumers)​

• Update Microsoft Edge for Android now. Open Google Play Store → My apps & games → Update Microsoft Edge (or check Edge Settings → About to trigger an in‑app update check). If MSRC or vendor release notes specify a fixed build, ensure your version equals or exceeds that build number. Multiple tracking sites list patched builds in the Android 139.x family; confirm in MSRC. (feedly.com)
• Avoid clicking unknown links. When receiving links by SMS or social apps, do not sign in after following an unsolicited link. Instead, open a new tab, type the known site address, or use a trusted bookmark.
• Disable autofill for high‑value accounts on mobile browsers and Android system where feasible, at least until you’ve updated.
• Enable available browser protections: keep SmartScreen (or equivalent phishing protection) enabled, set HTTPS‑only mode to on where supported, and avoid in‑app browsers for sensitive logins.
• Use multi‑factor authentication (MFA) for email, banking, and other critical accounts so stolen passwords alone are insufficient.

These measures reduce exposure while you update or while IT teams plan remedial deployments. (cybersecurity-help.cz)

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Enterprise guidance — 24 hours to 7 days​

• Inventory: map Microsoft Edge for Android usage across managed mobile devices. Use your MDM’s app inventory to identify Android devices with Edge installed and record version strings.
• Prioritize: prioritize devices that access corporate email, SSO portals, or high‑value applications for immediate updates.
• MDM push: publish an emergency policy to force or prompt Edge updates via Google Play or managed Google Play (for Android Enterprise/EAS-managed devices).
• User communications: issue an urgent security bulletin to users explaining the risk and advising them to avoid interactions with unsolicited links until devices are patched.
• Telemetry & detection: tune EDR and mobile threat detection to flag anomalous logins, suspicious webview navigation patterns, and high rates of failed authentication from mobile IPs.
• Fallback policies: if the patch cannot be rapidly deployed, consider temporarily blocking or constraining Edge for Android for high‑risk user groups until the update is applied.

Enterprise actions should be driven by the official MSRC “fixed in” version once the vendor clarifies the exact Edge build. In absence of direct MSRC consumable payload (due to the JS shell), rely on vendor release notes and produce a short verification test after patch rollout (open a controlled test URL and verify correct address bar binding).

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Detection and hunting tips for defenders​

• Monitor mobile device logs for sudden spikes in webview navigation to unknown domains or repeated redirects that match known spoofing patterns.
• Watch authentication logs for credential anomalies immediately following suspected mobile browsing sessions.
• Use web gateway logs to detect and block known malicious landing pages and high‑risk ad traffic.
• Test representative devices (Android device lab) with patched and unpatched Edge builds to validate whether UI elements (address bar, padlock, and permission dialogs) remain correctly bound during rapid redirects or overlayed content.

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Why this class of bug remains a chronic problem​

• The browser UI is a complex mix of renderer content and trusted chrome that must remain tightly bound; any timing or rendering mismatch is exploitable for spoofing.
• Mobile rendering engines and platform webviews vary across OS and vendor customizations, producing edge cases that are hard to exhaustively test.
• Humans are the weak link: attackers need only produce a convincing visual to succeed, and end‑user education is imperfect at scale.

Fixing these bugs often requires upstream Chromium changes and vendor‑specific hardening in the code that anchors origin chrome to an authenticated document. Consequently, coordinated disclosure and rapid patch rollout across Chromium downstreams is essential to reduce the attack window. (github.com)

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Responsible reporting and the CVE ID ambiguity​

The MSRC link provided uses a CVE identifier that—when scraped without JavaScript—does not expose the full advisory metadata, which led aggregators and mirrors to reference nearby CVEs (for example CVE‑2025‑49736 and CVE‑2025‑49755) for Microsoft Edge Android spoofing in August 2025. That means:

• Treat the class of vulnerability (Edge Android UI spoofing) as confirmed and actionable.
• Treat any specific CVE number or fixed build as unverified until you confirm via MSRC’s Security Update Guide in a JavaScript‑capable browser or Microsoft’s official release notes.

The prudent operational approach is to assume your Android Edge clients are at risk until you confirm they run a vendor‑stated fixed build.

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Recommendations — prioritized checklist​

• Immediate: Update Microsoft Edge for Android on all devices. If you manage devices, push the update via MDM and require installation within 24–72 hours. (feedly.com)
• Short term: Instruct users to avoid clicking links sent by unknown sources; use bookmarks or typed URLs for sensitive sites.
• Short term (admins): Block or monitor sign‑in attempts from devices that cannot be updated.
• Medium term: Validate fixes in a device lab and confirm the browser chrome is resistant to address bar and dialog spoofing under edge case navigation sequences.
• Ongoing: Apply continuous patch management for mobile browsers and educate users about mobile phishing vectors.

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Final assessment and risk outlook​

This Edge for Android spoofing advisory is emblematic of a recurring, high‑impact but technically moderate class of vulnerabilities: it is exploitable at scale through social engineering and web hosting, and the ultimate defense is timely patching combined with user and policy hardening. Aggregated public data indicates the vulnerability is network‑accessible, requires user interaction, and has been rated in the medium severity bracket by multiple trackers—meaning it should be treated as high priority for mobile fleets that handle corporate credentials or sensitive transactions. (nvd.nist.gov)
Because MSRC's interactive page requires JavaScript to render the full advisory, confirm the exact CVE mapping and “fixed in” build on the vendor page directly from a browser or via Microsoft’s official release notes before finalizing enterprise change windows. If there is any doubt about a device’s patch status, assume risk and remediate via forced update or temporary policy mitigations.

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Conclusion​

UI spoofing remains a favored attacker technique because it weaponizes human trust rather than platform memory flaws. The Microsoft Edge (Chromium‑based) for Android advisory reported in summer 2025 reiterates the urgent operational imperative: update now, validate patches, and harden user behavior for mobile browsing. Organizations that move quickly to inventory, update, and communicate will close the largest part of the risk window; those that delay can expect phishing campaigns leveraging spoofed mobile chrome to remain an effective attack vector. Confirm final version strings and vendor guidance in the Microsoft Security Update Guide (viewed via a JavaScript‑capable browser) and treat any remaining numeric discrepancies as items to verify before wide deployment. (feedly.com)

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Source: MSRC Security Update Guide - Microsoft Security Response Center