CVE-2026-75874: mozilla firefox, mozilla thunderbird

CVSS 10.0 (critical) · published 2026-08-18

Sandbox escape in the Remote Settings Client component. This vulnerability was fixed in Firefox 154, Thunderbird 154, Firefox ESR 115.40, Firefox ESR 140.15, Firefox ESR 153.2, Thunderbird 140.15, and Thunderbird 153.2.

Affected products (NVD): mozilla firefox, mozilla thunderbird

Fixed in (NVD): 154.0.0, 154.0

Weakness: CWE-693

Source: NVD CVE-2026-75874

References

• https://bugzilla.mozilla.org/show_bug.cgi?id=2039972
• https://www.mozilla.org/security/advisories/mfsa2026-74/
• https://www.mozilla.org/security/advisories/mfsa2026-78/
• https://www.mozilla.org/security/advisories/mfsa2026-83/
• https://www.mozilla.org/security/advisories/mfsa2026-84/
• https://www.mozilla.org/security/advisories/mfsa2026-85/
• https://www.mozilla.org/security/advisories/mfsa2026-87/
• https://www.mozilla.org/security/advisories/mfsa2026-88/

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