What’s Vulnerable › Vulnerabilities

CVE-2026-8953: Sandbox escape due to use-after-free in the Disability Access APIs component

• Severity: critical (CVSS 9.6 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.5% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-05-19 · updated 2026-10-14
• Weakness: CWE-416

Description

Sandbox escape due to use-after-free in the Disability Access APIs component. This vulnerability was fixed in Firefox 151, Firefox ESR 115.36, Firefox ESR 140.11, Thunderbird 151, and Thunderbird 140.11.

Affected products

• Mozilla Firefox: before 115.36.0; before 151.0.0; from 140.0 before 140.11.0 — fixed in 115.36.0, 140.11.0, 151.0.0
• Mozilla Thunderbird: before 140.11 — fixed in 140.11

How to fix

Upgrade to a fixed version: Mozilla Firefox 115.36.0, 140.11.0, 151.0.0; Mozilla Thunderbird 140.11. Check the vendor advisory for mitigations.

References

• https://bugzilla.mozilla.org/show_bug.cgi?id=2029511
• https://www.mozilla.org/security/advisories/mfsa2026-46/
• https://www.mozilla.org/security/advisories/mfsa2026-47/
• https://www.mozilla.org/security/advisories/mfsa2026-48/
• https://www.mozilla.org/security/advisories/mfsa2026-50/
• https://www.mozilla.org/security/advisories/mfsa2026-51/

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