Review reviewHigh

CVE-2026-3861

LY Corporation LINE client for iOS, line

LINE client for iOS versions prior to 26.3.0 contains a vulnerability in the in-app browser where opening a crafted web page can repeatedly trigger OS-level dialogs due to insufficient safeguards when handling arbitrary URL schemes, potentially causing the iOS device to become temporarily inoperable.

CVSS
7.1
EPSS
0.30%
22.8% percentile
CISA KEV
Not listed
Published
2026.04.16
PRIORITY ASSESSMENT

Review review

The CVSS severity warrants an early asset and exposure review.

Known exploitationNot established by KEV
Exploit probability0.30%
Technical severityCVSS 7.1

Vulnerability overview

LINE client for iOS versions prior to 26.3.0 contains a vulnerability in the in-app browser where opening a crafted web page can repeatedly trigger OS-level dialogs due to insufficient safeguards when handling arbitrary URL schemes, potentially causing the iOS device to become temporarily inoperable.

Affected product and versions

Product
LY Corporation LINE client for iOS, line
Affected versions
< 26.3.0
Fixed versions
26.3.0

Recommended response sequence

Confirm exposure before applying a vendor-supported change.

Full remediation guide
  1. 1
    Identify

    Confirm that LY Corporation LINE client for iOS, line and an affected version are present.

  2. 2
    Prioritize

    Combine exploitation signals with asset exposure and business criticality.

  3. 3
    Remediate

    Follow the vendor advisory or supported update path and preserve rollback options.

  4. 4
    Verify

    Recheck the version, service health, access paths, and relevant logs.

Technical data

CVSS vector
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:H/SC:N/SI:N/SA:L/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
CWE
CWE-451
CVE-2026-3861 — LY Corporation LINE client for iOS, line | SECUFOCUS NOW