CVE-2023-32214Network attack vector

Windows host hang via exposed protocol handlers

Published Jun 19, 2023 · Updated May 27, 2025

Denial of service in Mozilla Firefox before 113, Firefox ESR before 102.11, and Thunderbird before 102.11 allows remote attackers to hang Windows. The external-protocol handling path allowed web content to invoke the Windows ms-cxh and ms-cxh-full handlers by default, and those handlers can soft-lock the host. Exposure requires Windows and a crafted protocol-handler request from content; other operating systems are unaffected, and the bounded consequence is a host hang.

CVSS severity7.5
High
EPSS probability0.92%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
Coverage for this vulnerability

See if you're affected

Explore vulnerability checks for your environment with Hinoki.

Book a demo

Summary

What happened

Denial of service in Mozilla Firefox before 113, Firefox ESR before 102.11, and Thunderbird before 102.11 allows remote attackers to hang Windows. The external-protocol handling path allowed web content to invoke the Windows ms-cxh and ms-cxh-full handlers by default, and those handlers can soft-lock the host. Exposure requires Windows and a crafted protocol-handler request from content; other operating systems are unaffected, and the bounded consequence is a host hang.

The record

CVE
CVE-2023-32214
Published
Jun 19, 2023
Updated
May 27, 2025
Vendor
Mozilla
Product
Firefox
Classifications
T1499.004
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jun 19, 2023CVE publishedPublication date reported by the CVE source.
  2. May 27, 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 <113

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Mozilla · Firefoxversion=unspecified <113
Mozilla · Thunderbirdversion=unspecified <102.11
Mozilla · Firefox ESRversion=unspecified <102.11

Published CVSS scores

7.5NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

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

T1499.004Endpoint Denial of Service: Application or System Exploitation

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

See the directory against your own environment.

Your stack

Check the software in your environment

Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.

Book a demo