CVE-2026-100819

CRITICAL 9.6CVE-2026-100819 · Published 29/09/2026 · updated 05/10/2026

Package	Affected versions	Patched versions
firefox mozilla	`≥ 116.0, < 140.17.0≥ 141.0, < 153.4.0≥ 154.0.0, < 157.0.0< 115.42.0`	`140.17.0153.4.0157.0.0115.42.0`
thunderbird mozilla	`≥ 141.0, < 153.4.0≥ 154.0, < 157.0< 140.17.0`	`153.4.0157.0140.17.0`

Description

Sandbox escape due to incorrect boundary conditions in the XPCOM component. This vulnerability was fixed in Firefox ESR 153.4, Thunderbird 157, Thunderbird 140.17, Thunderbird 153.4, Firefox 157, Firefox ESR 115.42, and Firefox ESR 140.17.

References

bugzilla.mozilla.org/show_bug.cgi · Permissions Required
mozilla.org/security/advisories/mfsa2026-100 · Vendor Advisory
mozilla.org/security/advisories/mfsa2026-101 · Vendor Advisory
mozilla.org/security/advisories/mfsa2026-102 · Vendor Advisory
mozilla.org/security/advisories/mfsa2026-103 · Vendor Advisory
mozilla.org/security/advisories/mfsa2026-97 · Vendor Advisory
mozilla.org/security/advisories/mfsa2026-98 · Vendor Advisory
mozilla.org/security/advisories/mfsa2026-99 · Vendor Advisory

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