CVE-2022-46877Network attack vector

Spoofing via delayed fullscreen notification

Published Dec 22, 2022 · Updated Apr 15, 2025

Fullscreen notification bypass in Mozilla Firefox before 108 allows remote attackers to spoof browser chrome through a malicious webpage. The fullscreen controller waited for both the browser window and web content to enter fullscreen through several IPC state exchanges before showing the warning. A user must interact with attacker-controlled content, and delayed or suppressed warning UI can conceal the toolbar and URL bar and misrepresent the displayed site.

CVSS severity4.3
Medium
EPSS probability0.70%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Fullscreen notification bypass in Mozilla Firefox before 108 allows remote attackers to spoof browser chrome through a malicious webpage. The fullscreen controller waited for both the browser window and web content to enter fullscreen through several IPC state exchanges before showing the warning. A user must interact with attacker-controlled content, and delayed or suppressed warning UI can conceal the toolbar and URL bar and misrepresent the displayed site.

The record

CVE
CVE-2022-46877
Published
Dec 22, 2022
Updated
Apr 15, 2025
Vendor
Mozilla
Product
Firefox
Classifications
CWE-79, T1204
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Dec 22, 2022CVE publishedPublication date reported by the CVE source.
  2. Apr 15, 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 <108

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Mozilla · Firefoxversion=unspecified <108

Published CVSS scores

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

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-79Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
T1204User Execution

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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