CVE-2024-26283Public exploit

Top-origin script execution via unchecked deep links

Published Feb 22, 2024 · Updated Aug 29, 2024

Improper URL validation in Firefox for iOS before 123 allows attackers to execute scripts in top-origin sites through an external deep link. RouteBuilder passes the open-url parameter to navigation without restricting its scheme, bypassing the WebView's JavaScript-URI rejection. A victim must open the crafted firefox:// link from another app and approve the handoff; the script then runs in the displayed site's origin while the address bar can show a spoofed URL.

CVSS severity7.8
High
EPSS probability0.28%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Improper URL validation in Firefox for iOS before 123 allows attackers to execute scripts in top-origin sites through an external deep link. RouteBuilder passes the open-url parameter to navigation without restricting its scheme, bypassing the WebView's JavaScript-URI rejection. A victim must open the crafted firefox:// link from another app and approve the handoff; the script then runs in the displayed site's origin while the address bar can show a spoofed URL.

The record

CVE
CVE-2024-26283
Published
Feb 22, 2024
Updated
Aug 29, 2024
Vendor
Mozilla
Product
Firefox
Classifications
CWE-83, T1204.001
Attack vector
local
Privileges
unauthenticated

Timeline

How it unfolded

  1. Feb 22, 2024CVE publishedPublication date reported by the CVE source.
  2. Aug 29, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=0 <123

What conditions does exploitation require?

Attack vectorlocal
Required privilegesunauthenticated

What is affected?

Mozilla · Firefoxversion=0 <123
Mozilla · Firefox for iOSversion=unspecified <123

Published CVSS scores

7.8CISA-ADPCVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-83Improper Neutralization of Script in Attributes in a Web Page
T1204.001Malicious Link

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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