CVE-2026-100814 Firefox - Buffer Overflow

Firefox ESR and Firefox contain a buffer overflow caused by incorrect boundary conditions in the JavaScript Engine JIT component, letting attackers potentially execute arbitrary code, exploit requires crafted JavaScript code.

CVSS base score 8.8 /10
High
CISA KEV
Not listed
Public exploit
None known
Authentication
Not required
EPSS
0.24% chance of exploitation in 30 days
View the NVD record ↗

Details

Type
Buffer Overflow
Impact
Remote Code Execution
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
Published
29 September 2026
Updated
15 October 2026
Weakness
CWE-119

Vendor fix

Update to Firefox ESR 153.4, Firefox 157 or later.

Patching closes this CVE. It does not tell you which of your systems run the affected version, or what else is exposed alongside them.

References

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