CVE-2026-84120
MediumCVSS 5.4Exploitation Probability (EPSS)
Low risk14th percentile - higher than 14% of all known CVEs
Summary
Use-after-free in the Audio/Video component. This vulnerability was fixed in Firefox 155, Firefox ESR 115.40, Firefox ESR 140.15, Firefox ESR 153.2, Thunderbird 155, Thunderbird 140.15, and Thunderbird 153.2.
Risk Assessment
The vulnerability may lead to arbitrary code execution or browser crashes, potentially exposing the user to attacks.
Recommendation
It is recommended to update Firefox and Thunderbird to the versions indicated in the description or later.
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Original NVD description (English source)
Use-after-free in the Audio/Video component. This vulnerability was fixed in Firefox 155, Firefox ESR 115.40, Firefox ESR 140.15, Firefox ESR 153.2, Thunderbird 155, Thunderbird 140.15, and Thunderbird 153.2.
Vulnerability data from NVD (NIST) · CISA KEV · EPSS