CVE-2026-3861
Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.
NVD · uneditedLINE 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.
Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.
dbcve analysis · high confidenceThe LINE iOS client versions before 26.3.0 contain a denial-of-service vulnerability in the in-app browser component. Insufficient safeguards when handling arbitrary URL schemes allows a malicious web page to repeatedly trigger iOS OS-level dialogs, rendering the device temporarily unresponsive.
Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.
Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.
NVD · CPE data< 26.3.0CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.
From the vector- Attack vector
- Network
- Complexity
- Low
- Privileges
- None
- User interaction
- Required
- Scope
- Unchanged
- Confidentiality
- None
- Integrity
- None
- Availability
- High
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H
Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.
dbcve checksWork through these to decide whether this CVE applies to you.
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Check LINE iOS app versionOpen the LINE app, go to Settings > About LINE > Version, or check the version listed in the iOS App Store for the installed LINE appAffected if The displayed version number is lower than 26.3.0 (e.g., 26.2.9, 26.2.0, 25.x, etc.)
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Confirm in-app browser usageThe vulnerability is triggered when using the in-app browser feature within LINE (accessed via links opened in LINE chats)Affected if The in-app browser is routinely used to open web links within LINE conversations, which is the default behavior for many links
You are affected if your LINE iOS version is below 26.3.0 and you use the in-app browser to open links from LINE chats, as this allows malicious pages to repeatedly trigger iOS dialogs causing temporary unresponsiveness.
Generated from the published advisory. Verify against your own configuration.
Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.
dbcve · scoped26.3.0
Users must update to LINE iOS version 26.3.0 or later. For developers, the fix requires implementing rate-limiting or blocking of abusive URL scheme triggers within the in-app browser's URL handling logic.
LINE iOS version 26.3.0 or later
- Open the App Store on the iOS device
- Navigate to the Updates tab
- Locate LINE in the list of available updates
- Tap Update to install version 26.3.0 or later
- Alternatively, open the LINE app and go to Settings > About LINE > Check for updates to trigger the update process
- After updating, verify the version by going to Settings > About LINE to confirm version 26.3.0 or higher is installed
Generated from the published advisory — verify against the referenced sources before acting.
- Consultation1.0 h
- Implementation4.0 h
- Testing2.0 h
- Review / QA1.0 h
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Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2026-3861 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.
References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.
Primary sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2026-3861 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
No notes yet
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A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.
- Verified mitigations, workarounds, and config changes
- Version or environment caveats, and links to real fixes
- No weaponised exploit code, or anything meant to cause harm
- No spam, self-promotion, credentials, or personal data