CVE-2023-29542
CriticalCVSS 9.8Exploitation Probability (EPSS)
Elevated risk61th percentile - higher than 61% of all known CVEs
Summary
A newline in a filename could be used to bypass file extension security mechanisms that replace malicious extensions such as .lnk with .download, potentially leading to accidental execution of malicious code. This affects Firefox and Thunderbird on Windows: Firefox < 112, Firefox ESR < 102.10, and Thunderbird < 102.10.
Risk Assessment
A user could inadvertently execute a malicious file, potentially leading to workstation compromise and data theft.
Recommendation
Update Firefox to 112 or later, Firefox ESR to 102.10 or later, and Thunderbird to 102.10 or later. Educate users about the risks of opening unknown files.
Other vulnerabilities in Firefox and Thunderbird
See all- CVE-2026-113400Medium
An uninitialized memory vulnerability in the Audio/Video: cubeb component of Firefox and Thunderbird. The issue was fixed in Firefox 158.0.1 and Thunderbird 158.0.1.
- CVE-2026-113399Unknown
Incorrect boundary conditions in the SVG component. This vulnerability was fixed in Firefox 158.0.1 and Thunderbird 158.0.1.
- CVE-2025-13013Medium
A mitigation bypass vulnerability exists in the DOM: Core & HTML component of Firefox and Thunderbird. It was fixed in Firefox 145, Firefox ESR 140.5, Firefox ESR 115.30, Thunderbird 145, and Thunderbird 140.5.
Original NVD description (English source)
A newline in a filename could have been used to bypass the file extension security mechanisms that replace malicious file extensions such as .lnk with .download. This could have led to accidental execution of malicious code. *This bug only affects Firefox and Thunderbird on Windows. Other versions of Firefox and Thunderbird are unaffected.* This vulnerability affects Firefox < 112, Firefox ESR < 102.10, and Thunderbird < 102.10.
Vulnerability data from NVD (NIST) · CISA KEV · EPSS