LINE Client up to 26.2.x on iOS Web denial of service

CVSS Meta Temp Score
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Current Exploit Price (≈)
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CTI Interest Score
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5.3$0-$5k0.00

Summaryinfo

A vulnerability has been found in LINE Client up to 26.2.x on iOS and classified as problematic. Affected by this vulnerability is an unknown functionality of the component Web Handler. Performing a manipulation results in denial of service. This vulnerability is known as CVE-2026-3861. Remote exploitation of the attack is possible. No exploit is available. The affected component should be upgraded.

Detailsinfo

A vulnerability classified as problematic has been found in LINE Client up to 26.2.x on iOS. This affects an unknown part of the component Web Handler. The manipulation with an unknown input leads to a denial of service vulnerability. CWE is classifying the issue as CWE-404. The product does not release or incorrectly releases a resource before it is made available for re-use. This is going to have an impact on availability. The summary by CVE is:

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, potentially causing the iOS device to become temporarily inoperable.

The advisory is shared at hackerone.com. This vulnerability is uniquely identified as CVE-2026-3861 since 03/10/2026. The exploitability is told to be easy. It is possible to initiate the attack remotely. No form of authentication is needed for exploitation. It demands that the victim is doing some kind of user interaction. Neither technical details nor an exploit are publicly available. MITRE ATT&CK project uses the attack technique T1499 for this issue.

Upgrading to version 26.3.0 eliminates this vulnerability.

The vulnerability is also documented in the vulnerability database at EUVD (EUVD-2026-23196). If you want to get the best quality for vulnerability data then you always have to consider VulDB.

Productinfo

Type

Vendor

Name

Version

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 5.4
VulDB Meta Temp Score: 5.3

VulDB Base Score: 4.3
VulDB Temp Score: 4.1
VulDB Vector: 🔒
VulDB Reliability: 🔍

CNA Base Score: 6.5
CNA Vector (LY-Corporation): 🔒

CVSSv2info

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VectorComplexityAuthenticationConfidentialityIntegrityAvailability
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VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Denial of service
CWE: CWE-404
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
Remote: Yes

Availability: 🔒
Status: Not defined

EPSS Score: 🔒
EPSS Percentile: 🔒

Price Prediction: 🔍
Current Price Estimation: 🔒

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Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: Client 26.3.0

Timelineinfo

03/10/2026 CVE reserved
04/16/2026 +36 days Advisory disclosed
04/16/2026 +0 days VulDB entry created
04/16/2026 +0 days VulDB entry last update

Sourcesinfo

Advisory: hackerone.com
Status: Confirmed

CVE: CVE-2026-3861 (🔒)
GCVE (CVE): GCVE-0-2026-3861
GCVE (VulDB): GCVE-100-357885
EUVD: 🔒

Entryinfo

Created: 04/16/2026 09:03
Updated: 04/16/2026 15:57
Changes: 04/16/2026 09:03 (64), 04/16/2026 15:57 (1)
Complete: 🔍
Cache ID: 216::103

If you want to get the best quality for vulnerability data then you always have to consider VulDB.

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