Microsoft Teams for Android Vulnerability Could Expose Sensitive Data

Microsoft has patched an information disclosure vulnerability in Microsoft Teams for Android that could allow an authenticated attacker to expose sensitive data over a network. The flaw is tracked as CVE-2026-42835 and was disclosed as part of Microsoft’s June 2026 security updates.

The vulnerability affects Microsoft Teams for Android and carries a CVSS 3.1 score of 8.1. Microsoft rates the issue Important, while the NVD entry lists the severity as High based on the CVSS score.

The issue does not allow unauthenticated access. An attacker would need to be authorized, but the attack can be carried out over the network and does not require user interaction.

What CVE-2026-42835 allows attackers to do

CVE-2026-42835 stems from improper neutralization of special elements in output used by a downstream component. The weakness is classified as CWE-74, which is an injection-related vulnerability class.

According to the vulnerability description, successful exploitation could allow an authorized attacker to disclose information remotely. Microsoft’s scoring shows high confidentiality impact and high availability impact, with no integrity impact.

In practical terms, the concern is that Teams for Android could expose small portions of heap memory. Heap memory can sometimes contain sensitive runtime data, depending on what the app was processing at the time.

CVE	Product	Issue type	CVSS score	Impact
CVE-2026-42835	Microsoft Teams for Android	Information disclosure	8.1	Remote disclosure of sensitive data by an authorized attacker

Why the Teams for Android flaw matters

Microsoft Teams is widely used for business messaging, meetings, file sharing, and internal communications. The Android app can handle chats, channels, meetings, documents, calendars, and shared files, according to the official Microsoft Teams Google Play listing.

That makes information disclosure bugs important even when they do not allow full account takeover. Runtime memory can include data tied to active sessions, app state, cached information, or content being handled by the app.

The vulnerability requires low privileges. That means a low-privileged authenticated attacker could potentially trigger the issue if other attack conditions are met.

Affected versions and update status

NVD lists affected Microsoft Teams for Android versions as earlier than 1.0.76.2026111302. The same CVE record says the vulnerability was published on June 9, 2026, and last modified on June 17, 2026.

Google Play currently shows the Android app as updated on June 15, 2026. Users should not rely only on the update date shown in the store. They should open the store page and confirm that the latest version available for their device is installed.

Microsoft’s own support page says users can get the Teams mobile app through the Google Play Store. Enterprise administrators should use managed app deployment tools to confirm that mobile devices have received the fixed release.

No public exploitation reported at disclosure

Microsoft’s assessment lists exploitation as less likely. The flaw was not publicly disclosed before the advisory, and public exploit code was not listed as available at the time of disclosure.

That does not make the update optional. Mobile collaboration apps often carry sensitive business data, and attackers frequently review patches after release to understand what changed.

Organizations should treat Teams mobile updates as part of normal endpoint security, not as a lower priority than desktop patches. Phones and tablets often access the same chats, meeting links, files, and identity sessions as laptops.

How users can update Microsoft Teams on Android

Users should update Teams through the official Google Play page and avoid third-party APK sites. The official Teams app listing is published by Microsoft Corporation and is the safest update path for most Android users.

• Open Google Play on the Android device.
• Search for Microsoft Teams.
• Open the app page published by Microsoft Corporation.
• Tap Update if the option appears.
• Restart the app after updating.

Users who install work apps through a company portal should follow their organization’s mobile device management policy. Some companies control app updates through managed Google Play or Microsoft Intune.

What administrators should do now

Administrators should confirm which Android devices have Microsoft Teams installed and whether any managed devices still run a vulnerable version. Devices below the fixed version threshold should receive the update as soon as possible.

Teams mobile access policies also deserve review. Admins should check conditional access rules, device compliance requirements, app protection policies, and whether unmanaged devices can access business Teams data.

Microsoft’s Teams mobile app support guidance points users to official app stores, which helps reduce the risk of outdated or modified app builds being installed from unofficial sources.

Action	Why it matters
Update Teams for Android	Applies the fix for CVE-2026-42835.
Check managed Android devices	Finds devices that did not receive the latest app release.
Block sideloaded Teams APKs	Reduces exposure to outdated or tampered app builds.
Review conditional access policies	Limits access from non-compliant or unmanaged devices.
Monitor Teams access logs	Helps identify unusual mobile access patterns.

The main fix is straightforward: update Microsoft Teams for Android from the official store and verify that managed devices have received the patched build. Businesses that rely on Teams for sensitive communication should prioritize the update across all Android endpoints.

FAQ