CVE-2025-11720Network attack vector

User deception via truncated custom-tab hostnames

Published Oct 14, 2025 · Updated Oct 14, 2025

UI spoofing in Mozilla Firefox before 144 allows remote attackers to misrepresent a loaded Android custom-tab subdomain to users. The custom-tab interface reduces the displayed origin to the registrable site instead of the full hostname, so attacker-controlled content on one subdomain appears to belong to another. Exploitation requires a user to view and trust the custom tab; the resulting spoof can misdirect that user, with no reported code execution or service interruption.

CVSS severity8.1
High
EPSS probability0.27%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

UI spoofing in Mozilla Firefox before 144 allows remote attackers to misrepresent a loaded Android custom-tab subdomain to users. The custom-tab interface reduces the displayed origin to the registrable site instead of the full hostname, so attacker-controlled content on one subdomain appears to belong to another. Exploitation requires a user to view and trust the custom tab; the resulting spoof can misdirect that user, with no reported code execution or service interruption.

The record

CVE
CVE-2025-11720
Published
Oct 14, 2025
Updated
Oct 14, 2025
Vendor
Mozilla
Product
Firefox
Classifications
CWE-451, T1036
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Oct 14, 2025CVE publishedPublication date reported by the CVE source.
  2. Oct 14, 2025Record 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=unspecified <144

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Mozilla · Firefoxversion=unspecified <144

Published CVSS scores

8.1NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:N
8.1CISA-ADPCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:N

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.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

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 exploitUnconfirmed

Weakness, pattern, technique

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

Public exploit references

No public exploit references are available in this record.

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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