CVE-2026-109776: Race condition in the XPCOM component. This vulnerability was fixed in Firefox 158, Firefox ESR 153.5, Thunderbird 158, and Thunderbird 153.5.

PriorityP419medium4.2CVSS 3.1

AVNACHPRNUIRSUCLILAN

EPSS

0.14%

3.4th percentile

Race condition in the XPCOM component. This vulnerability was fixed in Firefox 158, Firefox ESR 153.5, Thunderbird 158, and Thunderbird 153.5.

Affected

4 ranges

Vendor	Product	Version range	Fixed in
mozilla	firefox	< Firefox 158	Firefox 158
mozilla	firefox_esr	< Firefox ESR 153.5	Firefox ESR 153.5
mozilla	thunderbird	< Thunderbird 153.5	Thunderbird 153.5
mozilla	thunderbird	< Thunderbird 158	Thunderbird 158

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