CVE-2026-16881 Overview
CVE-2026-16881 is a code injection vulnerability in the LINE Android application prior to version 26.7.2. The profile rendering component fails to validate or sandbox externally supplied script content embedded in profile templates. An attacker who places crafted content in a profile can trigger unintended code execution with the LINE application's privileges when a victim views that profile. LINE has deployed a server-side mitigation that also protects existing Android clients not yet updated to version 26.7.2.
Critical Impact
An attacker can achieve code execution within the LINE Android app's context by crafting a malicious profile, compromising confidentiality, integrity, and availability of user data accessible to the app.
Affected Products
- LINE Android app versions prior to 26.7.2
- Profile rendering component within the LINE mobile client
- Android devices with vulnerable LINE client installations
Discovery Timeline
- 2026-08-04 - CVE-2026-16881 published to NVD
- 2026-08-04 - Last updated in NVD database
Technical Details for CVE-2026-16881
Vulnerability Analysis
The vulnerability resides in the profile rendering pipeline of the LINE Android client. Profile templates accept externally supplied content and pass that content into a rendering context without adequate validation or sandboxing. When script content is embedded in a profile field, the renderer executes it inside the application's privilege boundary rather than isolating it. This yields client-side code injection triggered by the routine action of viewing a user profile. The LINE security advisory categorizes the flaw as code injection and confirms that both a client update and a server-side filter address the issue. See the LINE Security Advisory for CVE-2026-16881 for vendor details.
Root Cause
The profile rendering component does not sanitize or sandbox script content supplied through profile templates. The renderer trusts template input that can be controlled by any LINE user setting their own profile, violating the principle of treating externally supplied data as untrusted. Absent output encoding, script parsing restrictions, or a sandboxed rendering context, injected scripts execute with the LINE app's granted Android permissions.
Attack Vector
Exploitation requires an attacker to place crafted script content into a LINE profile field that will be rendered by a victim's client. Triggering the vulnerability requires user interaction — the victim must view the attacker-controlled profile. Once viewed, the injected code executes with the LINE application's privileges on the victim's Android device, potentially exposing message data, tokens, or other resources accessible to the app. The attack is network-reachable because profile content is distributed through LINE's platform to any user who opens the profile.
No public proof-of-concept exploit is available. Refer to the LINE Security Advisory for vendor-authored technical detail.
Detection Methods for CVE-2026-16881
Indicators of Compromise
- Unexpected outbound network connections originating from the LINE Android application to non-LINE infrastructure
- Anomalous file writes or content-provider access performed by the LINE app process shortly after viewing a profile
- LINE app crashes or rendering errors when opening specific profiles, which may indicate failed injection attempts
Detection Strategies
- Inventory mobile endpoints to identify LINE Android installations at versions below 26.7.2
- Monitor mobile device management (MDM) telemetry for the installed LINE application version across the fleet
- Correlate profile-view events in enterprise messaging usage logs, where available, with subsequent anomalous app behavior
Monitoring Recommendations
- Track LINE application update compliance through MDM reporting and flag devices that remain on vulnerable versions
- Monitor Android application logs for unexpected script execution or WebView-related activity from the LINE package
- Review network egress from mobile endpoints for connections to unrecognized domains initiated by the LINE process
How to Mitigate CVE-2026-16881
Immediate Actions Required
- Update the LINE Android app to version 26.7.2 or later through the Google Play Store
- Confirm through MDM that managed devices have received the updated LINE package
- Advise users to avoid opening profiles from unknown or untrusted LINE accounts until updates are applied
Patch Information
LINE Corporation released version 26.7.2 of the LINE Android app, which corrects the profile rendering component's handling of externally supplied script content. LINE has also deployed a server-side mitigation that filters malicious profile content, protecting Android clients that have not yet been updated. Vendor guidance is available in the LINE Security Advisory for CVE-2026-16881.
Workarounds
- Rely on LINE's deployed server-side mitigation, which filters malicious profile content before delivery to clients
- Restrict profile visibility settings and limit contact acceptance from unknown users to reduce exposure to crafted profiles
- Enforce mobile application update policies through MDM to prevent users from operating outdated LINE versions
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
