How severe is CVE-2026-3861?

CVE-2026-3861 has a CVSS 3.x base score of 6.5, rated medium severity. It is exploitable over network with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is none, integrity none, and availability high.

Is CVE-2026-3861 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (22nd percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2026-3861?

CVE-2026-3861 affects Linecorp Line. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2026-3861?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

Does CVE-2026-3861 have an EU (EUVD) identifier?

Yes. CVE-2026-3861 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-23196.

When was CVE-2026-3861 published?

CVE-2026-3861 was published on 2026-04-16 and last updated on 2026-07-08.

CVE-2026-3861

CVE-2026-3861 is a medium-severity vulnerability in Linecorp Line with a CVSS 3.x base score of 6.5. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-451.

Key facts

Severity: Medium (CVSS 3.x base score 6.5)
CVSS v4: 7.1
EPSS exploit prediction: 0% (22nd percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2026-23196
Weakness: CWE-451
Affected product: Linecorp Line
Published: 2026-04-16
Last modified: 2026-07-08

Description

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.

Frequently asked questions

What is CVE-2026-3861?: 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.
How severe is CVE-2026-3861?: CVE-2026-3861 has a CVSS 3.x base score of 6.5, rated medium severity. It is exploitable over network with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is none, integrity none, and availability high.
Is CVE-2026-3861 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (22nd percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-3861?: CVE-2026-3861 affects Linecorp Line. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2026-3861?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
Does CVE-2026-3861 have an EU (EUVD) identifier?: Yes. CVE-2026-3861 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-23196.
When was CVE-2026-3861 published?: CVE-2026-3861 was published on 2026-04-16 and last updated on 2026-07-08.

References

https://hackerone.com/reports/3422905

Affected products (1)

cpe:2.3:a:linecorp:line:*:*:*:*:*:iphone_os:*:*

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