What’s Vulnerable › Vulnerabilities

CVE-2026-109708: Sandbox escape due to incorrect boundary conditions in the Networking component

• Severity: critical (CVSS 9.6 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.3% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-10-13 · updated 2026-10-27
• Weakness: CWE-119

Description

Sandbox escape due to incorrect boundary conditions in the Networking component. This vulnerability was fixed in Firefox 158, Firefox ESR 153.5, Thunderbird 158, Thunderbird 153.5, and Firefox ESR 115.44.

References

• https://bugzilla.mozilla.org/show_bug.cgi?id=2059151
• https://www.mozilla.org/security/advisories/mfsa2026-106/
• https://www.mozilla.org/security/advisories/mfsa2026-108/
• https://www.mozilla.org/security/advisories/mfsa2026-109/
• https://www.mozilla.org/security/advisories/mfsa2026-110/
• https://www.mozilla.org/security/advisories/mfsa2026-119/

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