CVE-2026-100786: mozilla firefox, mozilla thunderbird

CVSS 9.6 (critical) · published 2026-09-29

Sandbox escape due to use-after-free in the Graphics 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.

Affected products (NVD): mozilla firefox, mozilla thunderbird

Fixed in (NVD): 115.42.0, 140.17.0, 153.4.0, 157.0.0, 157.0

Weakness: CWE-416

Source: NVD CVE-2026-100786

References

• https://bugzilla.mozilla.org/show_bug.cgi?id=2071067
• https://www.mozilla.org/security/advisories/mfsa2026-100/
• https://www.mozilla.org/security/advisories/mfsa2026-101/
• https://www.mozilla.org/security/advisories/mfsa2026-102/
• https://www.mozilla.org/security/advisories/mfsa2026-103/
• https://www.mozilla.org/security/advisories/mfsa2026-97/
• https://www.mozilla.org/security/advisories/mfsa2026-98/
• https://www.mozilla.org/security/advisories/mfsa2026-99/

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