CVE-2026-5731

Memory safety bugs fixed in Firefox ESR 115.34.1, Firefox ESR 140.9.1, Thunderbird ESR 140.9.1, Firefox 149.0.2 and Thunderbird 149.0.2

CVSS 9.8 CRITICALEPSS 0.3%CWE-119 CWE-787

Vexday Risk Score

28Baixo

Decisão SSVC (CISA)

Track

Sem sinal de exploração → monitorar

CVSS 9.8EPSS 0.3%KEV nãoPoC —Nuclei —Metasploit —Patch referenciado

Ciclo de vida

07 abr 2026Publicada no NVD

Recomendação: Monitorar — sem sinal de exploração no momento.

Memory safety bugs present in Firefox ESR 115.34.0, Firefox ESR 140.9.0, Thunderbird ESR 140.9.0, Firefox 149.0.1 and Thunderbird 149.0.1. Some of these bugs showed evidence of memory corruption and we presume that with enough effort some of these could have been exploited to run arbitrary code. This vulnerability was fixed in Firefox 149.0.2, Firefox ESR 115.34.1, Firefox ESR 140.9.1, Thunderbird 149.0.2, and Thunderbird 140.9.1.

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Produtos afetados

Mozilla · Firefox Mozilla · Thunderbird

Referências