CVE-2025-8043Public exploitNetwork attack vector

URL spoofing via origin-hiding truncation

Published Jul 22, 2025 · Updated Apr 13, 2026

URL spoofing in Mozilla Firefox Focus before 141 allows remote attackers to conceal a site's registrable domain with a long subdomain. The address bar truncates long URLs from the origin end and displays the opening subdomain text instead of preserving and highlighting the eTLD+1 domain. Exploitation requires a user to open a crafted URL; the misleading security indicator can make an attacker-controlled site appear to belong to a trusted domain.

CVSS severity9.8
Critical
EPSS probability0.38%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

URL spoofing in Mozilla Firefox Focus before 141 allows remote attackers to conceal a site's registrable domain with a long subdomain. The address bar truncates long URLs from the origin end and displays the opening subdomain text instead of preserving and highlighting the eTLD+1 domain. Exploitation requires a user to open a crafted URL; the misleading security indicator can make an attacker-controlled site appear to belong to a trusted domain.

The record

CVE
CVE-2025-8043
Published
Jul 22, 2025
Updated
Apr 13, 2026
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-451, T1036
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jul 22, 2025CVE publishedPublication date reported by the CVE source.
  2. Apr 13, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Affected buildAffected product and version details are unavailable.

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

9.8CISA-ADPCVSS:3.1/AV:N/AC:L/PR:N/UI:N/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)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-451User Interface (UI) Misrepresentation of Critical Information
T1036Masquerading

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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