CVE-2026-109783

Low risk· EPSS 9%

Published: 13/10/2026(UTC)Updated: 13/10/2026(UTC)Translated: 14/10/2026(UTC)NVD NIST

Exploitation Probability (EPSS)

Low risk

0.20%

9th percentile - higher than 9% of all known CVEs

Summary

Mitigation bypass in the File Handling component. This vulnerability was fixed in Firefox ESR 153.5 and Thunderbird 153.5.

Risk Assessment

A security mitigation bypass in file handling may allow an attacker to circumvent protective measures, potentially leading to further exploitation or unintended actions. The risk affects users of outdated browser and email client versions.

Recommendation

Update Firefox ESR to version 153.5 or later and Thunderbird to version 153.5 or later. Ensure updates are deployed across all workstations.

Other vulnerabilities in Firefox ESR / Thunderbird

CVE-2026-109782Low risk· EPSS 9%
Mitigation bypass in the File Handling component. This vulnerability was fixed in Firefox ESR 153.5 and Thunderbird 153.5.

Original NVD description (English source)

Mitigation bypass in the File Handling component. This vulnerability was fixed in Firefox ESR 153.5 and Thunderbird 153.5.

Vulnerability data from NVD (NIST) · CISA KEV · EPSS