CVE-2025-1019Public exploitNetwork attack vector

Spoofing via hidden fullscreen notification

Published Feb 4, 2025 · Updated Apr 13, 2026

Improper UI-layer restriction in Mozilla Firefox and Thunderbird before 135 allows remote attackers to spoof trusted content. Repeated reportValidity calls from a popup steal focus because popup display omits SWP_NOOWNERZORDER, raising the owner above the fullscreen notification. User interaction is required to enter fullscreen, and the demonstrated consequence is visual spoofing rather than data disclosure or code execution.

CVSS severity4.3
Medium
EPSS probability0.36%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Improper UI-layer restriction in Mozilla Firefox and Thunderbird before 135 allows remote attackers to spoof trusted content. Repeated reportValidity calls from a popup steal focus because popup display omits SWP_NOOWNERZORDER, raising the owner above the fullscreen notification. User interaction is required to enter fullscreen, and the demonstrated consequence is visual spoofing rather than data disclosure or code execution.

The record

CVE
CVE-2025-1019
Published
Feb 4, 2025
Updated
Apr 13, 2026
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-1021, T1036
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Feb 4, 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

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

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

No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-1021Improper Restriction of Rendered UI Layers or Frames
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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