CVE-2026-86853— Repeated external URL scheme launches could potentially cause a denial of service in Firefox for iOS
Quick assessment
Affected
Mozilla Firefox for iOS
Exploitation
No confirmed in-the-wild exploitation; assess based on exposure
Recommended action
Check the vendor advisory and references for a fixed version. If immediate upgrade is impossible, restrict exposure and increase monitoring.
Mozilla Firefox是Mozilla基金会开源的一款网页浏览器。 Mozilla Firefox 155.1之前版本存在处理逻辑错误漏洞，该漏洞源于恶意网页可反复触发外部URL schemes，可能导致系统提示或外部应用程序启动，并造成浏览器暂时无法使用直至页面被关闭。
Possible ATT&CK Techniques 1 AI
T1565.001 · Stored Data ManipulationAffected Version Matrix 1
| Vendor | Product | Version Range | Status |
|---|---|---|---|
| Mozilla | Firefox for iOS | 155.1≤ * |
unaffected |
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I. Basic Information for CVE-2026-86853
Vulnerability Information
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Vulnerability Title
Repeated external URL scheme launches could potentially cause a denial of service in Firefox for iOS
Source: CVE Program / CVE List V5
Vulnerability Description
A malicious webpage could repeatedly trigger external URL schemes, causing system prompts or external application launches. This could make Firefox for iOS temporarily unusable until the page is closed. This vulnerability was fixed in Firefox for iOS 155.1.
Source: CVE Program / CVE List V5
CVSS Information
N/A
Source: CVE Program / CVE List V5
Vulnerability Type
N/A
Source: CVE Program / CVE List V5
Vulnerability Title
Mozilla Firefox 处理逻辑错误漏洞
Source: CNNVD (China National Vulnerability Database)
Vulnerability Description
Mozilla Firefox是Mozilla基金会开源的一款网页浏览器。 Mozilla Firefox 155.1之前版本存在处理逻辑错误漏洞，该漏洞源于恶意网页可反复触发外部URL schemes，可能导致系统提示或外部应用程序启动，并造成浏览器暂时无法使用直至页面被关闭。
Source: CNNVD (China National Vulnerability Database)
CVSS Information
N/A
Source: CNNVD (China National Vulnerability Database)
Vulnerability Type
N/A
Source: CNNVD (China National Vulnerability Database)
Affected Products
| Vendor | Product | Affected Versions | CPE | Subscribe |
|---|---|---|---|---|
| Mozilla | Firefox for iOS | 155.1 ~ * | - |
|
II. Public POCs for CVE-2026-86853
| # | POC Description | Source Link | Shenlong Link |
|---|
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Vendor Advisories for CVE-2026-86853 (1)
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V. Comments for CVE-2026-86853
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