CVE-2026-3861 Denial of service in LINE client for iOS
Attackers can cause iOS devices to become temporarily inoperable by triggering repeated OS dialogs via crafted web pages in the LINE app's in-app browser.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- A user has to click or open something
- Fix
- None listed
What is CVE-2026-3861?
CVE-2026-3861 is a high-severity denial of service vulnerability in Linecorp Line, published on 16 Apr 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.
Official 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.
Weakness: CWE-451
Which versions are affected by CVE-2026-3861?
It affects 1 product.
Products include Linecorp Line.
How do I fix CVE-2026-3861?
No fix has been published for CVE-2026-3861 yet. Limit exposure of the affected software until one is available.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is CVE-2026-3861 being exploited?
There is no known exploitation of CVE-2026-3861 in the wild and no public exploit code.
Other vulnerabilities in Linecorp Line
Sources
Also known as GHSA-rc35-963c-p69f.