Description
Websites directing users to long URLs that caused eliding to occur in the location view could leverage the truncating behavior to potentially trick users into thinking they were on a different webpage. This vulnerability was fixed in Focus 138.
Published: 2025-04-30
Score: 4.3 Medium
EPSS: < 1% Very Low
KEV: No
Impact: Address bar spoofing
Action: Immediate Update
AI Analysis

Impact

The flaw allows a website to craft a very long URL that, when loaded in Firefox Focus, is truncated in the location bar, potentially displaying a misleading shorter address. The truncation may cause a user to erroneously believe they are on a different site, thus facilitating phishing or social engineering attacks. The weakness is represented by CWE‑451 (Information Exposure) and CWE‑601 (Intentional Redirect), indicating that the vulnerability is a result of improper handling of user-visible data rather than a code execution flaw.

Affected Systems

The issue affects Mozilla Focus on iPhone OS, specifically all builds prior to version 138. Users running an earlier Focus release are susceptible to the URL truncation behavior.

Risk and Exploitability

The CVSS score of 4.3 classifies the impact as low, and the EPSS score of less than 1% indicates a very low probability of exploitation in the wild. The vulnerability is not listed in the CISA KEV catalog, and it is a client‑side UI bug that requires a user to visit a crafted long URL. Consequently, the overall risk is moderate in that it could support phishing attempts but does not enable remote code execution or system compromise.

Generated by OpenCVE AI on April 20, 2026 at 17:10 UTC.

Remediation

No vendor fix or workaround currently provided.

OpenCVE Recommended Actions

  • Upgrade Mozilla Focus to version 138 or later to eliminate the URL truncation flaw.
  • Avoid interacting with websites that employ excessively long URLs designed to truncate; verify the full address by hovering over or copying the link.
  • Consider using an alternative mobile browser for sites where address bar integrity is critical.

Generated by OpenCVE AI on April 20, 2026 at 17:10 UTC.

Tracking

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Advisories
Source ID Title
EUVD EUVD EUVD-2025-12733 Websites directing users to long URLs that caused eliding to occur in the location view could leverage the truncating behavior to potentially trick users into thinking they were on a different webpage This vulnerability affects Focus < 138.
History

Mon, 13 Apr 2026 15:00:00 +0000

Type Values Removed Values Added
Description Websites directing users to long URLs that caused eliding to occur in the location view could leverage the truncating behavior to potentially trick users into thinking they were on a different webpage This vulnerability affects Focus < 138. Websites directing users to long URLs that caused eliding to occur in the location view could leverage the truncating behavior to potentially trick users into thinking they were on a different webpage. This vulnerability was fixed in Focus 138.
Title Firefox Focus elide URL allows address bar spoofing

Mon, 12 May 2025 20:00:00 +0000

Type Values Removed Values Added
First Time appeared Mozilla
Mozilla firefox Focus
Weaknesses CWE-601
CPEs cpe:2.3:a:mozilla:firefox_focus:*:*:*:*:*:iphone_os:*:*
Vendors & Products Mozilla
Mozilla firefox Focus

Mon, 12 May 2025 16:15:00 +0000

Type Values Removed Values Added
Weaknesses CWE-451
Metrics cvssV3_1

{'score': 4.3, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:N/A:N'}

ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Wed, 30 Apr 2025 16:45:00 +0000

Type Values Removed Values Added
Description Websites directing users to long URLs that caused eliding to occur in the location view could leverage the truncating behavior to potentially trick users into thinking they were on a different webpage This vulnerability affects Focus < 138.
References

Subscriptions

Mozilla Firefox Focus
cve-icon MITRE

Status: PUBLISHED

Assigner: mozilla

Published:

Updated: 2026-04-13T14:28:36.100Z

Reserved: 2025-04-21T16:01:02.407Z

Link: CVE-2025-3859

cve-icon Vulnrichment

Updated: 2025-04-30T17:15:05.584Z

cve-icon NVD

Status : Modified

Published: 2025-04-30T17:15:50.903

Modified: 2026-04-13T15:16:58.203

Link: CVE-2025-3859

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2026-04-20T17:15:12Z

Weaknesses