CVE-2026-86853

Repeated external URL scheme launches could potentially cause a denial of service in Firefox for iOS

Published: Sep 8, 2026Updated: Sep 8, 2026 Sources: CVE List NVDCWE-451

4.3MEDIUM

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.

No summary for this CVE yet.

CVSS Vector Breakdown

Exploitability

AV:NAttack Vector

Network

AC:LAttack Complexity

Low

PR:NPrivileges Required

None

UI:RUser Interaction

Required

Scope

S:UScope

Unchanged

Impact

C:NConfidentiality

None

I:NIntegrity

None

A:LAvailability

Low

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Weaknesses

CWE-451

Affected Products

Mozilla

oss-project·USaka mozilla corp.

Firefox for iOS

Consumer Software

Exploitability

No known exploits, KEV entries, or remediation guidance available for this vulnerability yet.

References

https://bugzilla.mozilla.org/show_bug.cgi?id=1847631

bugzilla.mozilla.org

https://www.mozilla.org/security/advisories/mfsa2026-89/

mozilla.org

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