CVE-2026-109740
—UnscoredPublished 13 Oct 2026 · NVD status: Deferred · AI triage by gemini-3.8-flash
- Attack vector
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- Complexity
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- Privileges needed
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- User interaction
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- Impact
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- Weakness
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Impact
Attackers can escape the browser sandbox on Windows to run code with the privileges of the parent process. They need a user to visit a malicious website or open a malicious message in an affected client.
Root cause
Incorrect boundary conditions in the Widget: Win32 component allow sandbox escape.
Affected systems
Firefox before 158, Firefox ESR before 153.5, Thunderbird before 158, and Thunderbird ESR before 153.5 on Windows.
Fix & remediation
Upgrade to Firefox 158, Firefox ESR 153.5, Thunderbird 158, or Thunderbird 153.5. No interim workarounds are provided.
AI-suggested. Run it in staging first and check it against the vendor advisory. Why?
NVD description
Sandbox escape due to incorrect boundary conditions in the Widget: Win32 component. This vulnerability was fixed in Firefox 158, Firefox ESR 153.5, Thunderbird 158, and Thunderbird 153.5.