CVE-2026-109705

CRITICALCVSS 9.6/10

Last modified

CVE-2026-109705 is a critical-severity vulnerability rated 9.6/10 on the CVSS scale. Sandbox escape, site isolation issue due to incorrect boundary conditions, use-after-free in the Networking component. This vulnerability was fixed in Firefox 158, Firefox ESR 153.5, Thunderbird 158, and Thunderbird 153.5..

Description

Sandbox escape, site isolation issue due to incorrect boundary conditions, use-after-free in the Networking component. This vulnerability was fixed in Firefox 158, Firefox ESR 153.5, Thunderbird 158, and Thunderbird 153.5.

Metrics

Weakness Enumeration

Affected Software

Source: CNA advisory (CVE.org). NVD analysis pending.

VendorProductVersions
MozillaFirefoxAll versions

References

Timeline

Published
Last Modified
Status
Deferred

Frequently Asked Questions

What is CVE-2026-109705?
Sandbox escape, site isolation issue due to incorrect boundary conditions, use-after-free in the Networking component. This vulnerability was fixed in Firefox 158, Firefox ESR 153.5, Thunderbird 158, and Thunderbird 153.5.
How severe is CVE-2026-109705?
CVE-2026-109705 has a CVSS score of 9.6/10 (CRITICAL severity).
How do I fix CVE-2026-109705?
Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

How Strix Helps

Related CVEs from 2026

Are you affected by CVE-2026-109705?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST