In-App Browser Vulnerability in LINE Client for iOS
CVE-2026-3861

7.1HIGH

Key Information:

Vendor: Ly Corporation
Status: Line Client For iOS
Vendor: CVE Published:; 16 April 2026

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What is CVE-2026-3861?

The LINE client for iOS, prior to version 26.3.0, has a significant flaw in its in-app browser that allows specially crafted web pages to trigger repetitive OS-level dialog prompts. This behavior can lead to the iOS device becoming temporarily inoperable, causing user frustration and potential workflow interruptions. Users of affected versions should upgrade to the latest version to mitigate this issue.

Affected Version(s)

LINE client for iOS 26.3.0

References

https://hackerone.com/reports/3422905

CVSS V4

Score:

7.1

Severity:

HIGH

Confidentiality:

None

Integrity:

None

Availability:

High

Attack Vector:

Network

Attack Complexity:

Low

Attack Required:

None

Privileges Required:

Undefined

User Interaction:

Unknown

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Timeline

Vulnerability published
Apr 16, 2026
Vulnerability Reserved
Mar 10, 2026

CVE-2026-3861 Data

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