CVE-2025-5265
MediumCVSS 4.8Exploitation Probability (EPSS)
Low risk10th percentile - higher than 10% of all known CVEs
Summary
The 'Copy as cURL' feature in Firefox for Windows improperly escapes the ampersand character, which could allow an attacker to trick a user into using a crafted command, potentially leading to local code execution on the user's system. This bug only affects Firefox for Windows; other versions are unaffected. Fixed in Firefox 139, Firefox ESR 115.24, Firefox ESR 128.11, Thunderbird 139, and Thunderbird 128.11.
Risk Assessment
An attacker could exploit this vulnerability to execute malicious code on the victim's machine, potentially leading to full system compromise.
Recommendation
Update Firefox or Thunderbird to a patched version (Firefox 139, Firefox ESR 115.24, Firefox ESR 128.11, Thunderbird 139, Thunderbird 128.11).
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- CVE-2026-109740Critical
Sandbox escape due to incorrect boundary conditions in the Widget: Win32 component. The flaw was fixed in Firefox 158, Firefox ESR 153.5, Thunderbird 158, and Thunderbird 153.5.
Original NVD description (English source)
Due to insufficient escaping of the ampersand character in the “Copy as cURL” feature, an attacker could trick a user into using this command, potentially leading to local code execution on the user's system. *This bug only affects Firefox for Windows. Other versions of Firefox are unaffected.*. This vulnerability was fixed in Firefox 139, Firefox ESR 115.24, Firefox ESR 128.11, Thunderbird 139, and Thunderbird 128.11.
Vulnerability data from NVD (NIST) · CISA KEV · EPSS