CVE-2022-22746Network attack vector

Fullscreen window spoofing via reportValidity focus race

Published Dec 22, 2022 · Updated Apr 16, 2025

Fullscreen UI spoofing in Mozilla Firefox before 96, Firefox ESR before 91.5, and Thunderbird before 91.5 lets remote attackers conceal a warning. A reportValidity call can steal focus during a fullscreen transition, creating a race that lets attacker-controlled content overlap the fullscreen notification. Only Windows is affected; reaching Thunderbird requires a browser-like context because scripting is disabled while reading email.

CVSS severity5.9
Medium
EPSS probability0.59%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Fullscreen UI spoofing in Mozilla Firefox before 96, Firefox ESR before 91.5, and Thunderbird before 91.5 lets remote attackers conceal a warning. A reportValidity call can steal focus during a fullscreen transition, creating a race that lets attacker-controlled content overlap the fullscreen notification. Only Windows is affected; reaching Thunderbird requires a browser-like context because scripting is disabled while reading email.

The record

CVE
CVE-2022-22746
Published
Dec 22, 2022
Updated
Apr 16, 2025
Vendor
Mozilla
Product
Firefox
Classifications
CWE-362, T1036
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Dec 22, 2022CVE publishedPublication date reported by the CVE source.
  2. Apr 16, 2025Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

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

  1. Affected versionversion=unspecified <96

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Mozilla · Firefoxversion=unspecified <96
Mozilla · Thunderbirdversion=unspecified <91.5
Mozilla · Firefox ESRversion=unspecified <91.5

Published CVSS scores

5.9CISA-ADPCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:N
5.9NIST NVDCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/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-362Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition')
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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