CVE-2026-84124

published 2026-09-01

CVE-2026-84124: Use-after-free in the DOM: Core & HTML component. This vulnerability was fixed in Firefox 155, Firefox ESR 140.15, Firefox ESR 153.2, Thunderbird 155…

Priority P4 26 medium 5.4 CVSS 3.1

AV N AC L PR N UI R S U C L I L A N

Use-after-free in the DOM: Core & HTML component. This vulnerability was fixed in Firefox 155, Firefox ESR 140.15, Firefox ESR 153.2, Thunderbird 155, Thunderbird 140.15, and Thunderbird 153.2.

Affected

12 ranges

Vendor	Product	Version range	Fixed in
mozilla	firefox	< Firefox 155	Firefox 155
mozilla	firefox	< 140.15.0	140.15.0
mozilla	firefox	>= 141.0.0 < 153.2.0	153.2.0
mozilla	firefox	>= 154.0.0 < 155.0.0	155.0.0
mozilla	firefox_esr	< Firefox ESR 153.2	Firefox ESR 153.2
mozilla	firefox_esr	< Firefox ESR 140.15	Firefox ESR 140.15
mozilla	thunderbird	< Thunderbird 140.15	Thunderbird 140.15
mozilla	thunderbird	< Thunderbird 155	Thunderbird 155
mozilla	thunderbird	< Thunderbird 153.2	Thunderbird 153.2
mozilla	thunderbird	< 140.15.0	140.15.0
mozilla	thunderbird	>= 141.0 < 153.2.0	153.2.0
mozilla	thunderbird	>= 154.0 < 155.0	155.0

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