CVE-2026-65769: Microsoft Teams Information Disclosure

CVE-2026-65769 Overview

CVE-2026-65769 is an information disclosure vulnerability in Microsoft Teams Mobile. The flaw is classified under [CWE-200] (Exposure of Sensitive Information to an Unauthorized Actor). An unauthenticated attacker can trigger the vulnerability over a network when a user performs a required interaction, resulting in disclosure of confidential information.

Critical Impact
An attacker can disclose sensitive Microsoft Teams Mobile information across a network without prior authentication, provided the target user interacts with attacker-supplied content.

Affected Products

Microsoft Teams Mobile

Discovery Timeline

2026-08-11 - CVE-2026-65769 published to the National Vulnerability Database (NVD)
2026-08-11 - Last updated in the NVD database

Technical Details for CVE-2026-65769

Vulnerability Analysis

CVE-2026-65769 is an information disclosure weakness in Microsoft Teams Mobile. Microsoft classifies the issue as exposure of sensitive information to an unauthorized actor, mapped to [CWE-200]. The vulnerability affects confidentiality only. It does not permit modification of data and does not degrade availability of the service.

Exploitation occurs over the network and requires user interaction. Common interaction patterns for mobile Teams vulnerabilities include opening a crafted message, joining a maliciously prepared meeting, or previewing attacker-supplied content. The attacker does not need prior credentials on the target tenant or device.

The EPSS model estimates a probability of 0.676% at percentile 49.018 as of 2026-08-13, indicating the vulnerability is not currently trending toward mass exploitation. No public proof-of-concept, exploit code, or CISA KEV listing is associated with this CVE at the time of publication.

Root Cause

Microsoft has not publicly detailed the specific component or code path. The [CWE-200] mapping indicates the application returns or renders data that should have been restricted to authorized principals. Refer to the Microsoft Security Update CVE-2026-65769 advisory for vendor-authoritative technical details.

Attack Vector

The attack is remote and network-based. A user of the Microsoft Teams Mobile application must interact with attacker-controlled content, such as a message, link, invite, or shared resource. Successful exploitation returns sensitive information to the attacker without altering system state on the target device.

No verified public code examples are available. See the vendor advisory for authoritative technical details.

Detection Methods for CVE-2026-65769

Indicators of Compromise

Microsoft Teams Mobile clients running versions prior to the fixed build referenced in the Microsoft Security Response Center (MSRC) advisory.
Unexpected outbound connections from mobile devices to unfamiliar domains immediately after a Teams message, invite, or link interaction.
Anomalous Teams chat or channel messages containing crafted links, attachments, or embedded content originating from external tenants.

Detection Strategies

Monitor Microsoft 365 audit logs for unusual Teams message activity from external or newly created tenants targeting mobile users.
Correlate mobile device network telemetry with Teams interaction events to identify data egress following user interaction with untrusted content.
Track application version inventory across managed mobile endpoints to identify devices running vulnerable Teams Mobile builds.

Monitoring Recommendations

Ingest Microsoft Teams and Entra ID logs into a centralized SIEM for correlation with mobile device telemetry.
Alert on external federation events and cross-tenant messages that precede user-initiated content interactions.
Baseline outbound network traffic from mobile devices and alert on deviations following Teams client activity.

How to Mitigate CVE-2026-65769

Immediate Actions Required

Update Microsoft Teams Mobile on iOS and Android to the fixed version identified in the Microsoft Security Update CVE-2026-65769 advisory.
Enforce automatic application updates through mobile device management (MDM) policies to reduce exposure windows.
Restrict external federation and guest access in Microsoft Teams administration where business requirements allow.
Communicate awareness guidance to users, instructing them not to interact with unsolicited Teams messages, invites, or links.

Patch Information

Microsoft has released a security update through standard mobile application store channels. Consult the Microsoft Security Update CVE-2026-65769 advisory for the specific fixed version and deployment guidance.

Workarounds

Disable or restrict external communications in Microsoft Teams admin center until all mobile clients are updated.
Apply conditional access policies requiring compliant, up-to-date Teams Mobile clients before granting access to organizational resources.
Educate users to verify sender identity and avoid interacting with unexpected shared content on mobile Teams clients.

bash

# Example: enforce minimum Teams Mobile app version via Microsoft Intune app protection policy
# Configure through Endpoint Manager > Apps > App protection policies > Conditional launch
# Setting: Min app version
# Action: Block access (or Warn) if version is below the MSRC-listed fixed build