CVE-2026-2919Network attack vector

Domain spoofing via stalled navigation and iframe redirect

Published Mar 9, 2026 · Updated Mar 9, 2026

Origin spoofing in Mozilla Firefox Focus before 148.2 allows remote attackers to show controlled content under trusted domains. A malicious script stalls a _self navigation at an invalid port, then redirects an iframe while the browser UI retains the trusted domain. Reaching malicious web content requires user interaction, but the spoof appears without further interaction; the demonstrated consequence is deceptive content display.

CVSS severity4.3
Medium
EPSS probability0.18%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Origin spoofing in Mozilla Firefox Focus before 148.2 allows remote attackers to show controlled content under trusted domains. A malicious script stalls a _self navigation at an invalid port, then redirects an iframe while the browser UI retains the trusted domain. Reaching malicious web content requires user interaction, but the spoof appears without further interaction; the demonstrated consequence is deceptive content display.

The record

CVE
CVE-2026-2919
Published
Mar 9, 2026
Updated
Mar 9, 2026
Vendor
Mozilla
Product
Firefox Focus
Classifications
CWE-451
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Mar 9, 2026CVE publishedPublication date reported by the CVE source.
  2. Mar 9, 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?

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

  1. Affected versionversion=unspecified <148.2

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Mozilla · Firefox Focusversion=unspecified <148.2

Published CVSS scores

4.3CISA ADPCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:L/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.

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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 exploitUnconfirmed

Weakness, pattern, technique

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

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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