Is CVE-2022-34478 actively exploited?

Yes. CVE-2022-34478 is listed in the CISA Known Exploited Vulnerabilities (KEV) catalog, which means exploitation in the wild has been confirmed.

Can CVE-2022-34478 be exploited remotely?

The attack vector of CVE-2022-34478 has not been classified yet.

What is the CVSS score of CVE-2022-34478?

CVE-2022-34478 has not received a CVSS score yet.

HOME VULNERABILITIESCVE-2022-34478

UNKNOWNCISA KEVIN THE WILD

CVE-2022-34478

Published: April 11, 2026

Official Description

The ms-msdt, search, and search-ms protocols deliver content to Microsoft applications, bypassing the browser, when a user accepts a prompt. These applications have had known vulnerabilities, exploited in the wild (although we know of none exploited through Thunderbird), so in this release Thunderbird has blocked these protocols from prompting the user to open them.*This bug only affects Thunderbird on Windows. Other operating systems are unaffected.*. This vulnerability affects Firefox < 102, Firefox ESR < 91.11, Thunderbird < 102, and Thunderbird < 91.11.

NVD Source

Technical Analysis

CVE-2022-34478 requires local access, meaning attackers must already have a foothold on the target system.

Exploitation requires some privileges, which limits the exposure to scenarios where an attacker has already gained initial access.

CISA has added CVE-2022-34478 to the Known Exploited Vulnerabilities (KEV) catalog, confirming active exploitation in the wild. U.S. federal agencies are required to patch this within the mandated timeframe, and all organizations should treat remediation as urgent.