CVE-2026-109782

Firefox: Mitigation bypass in the File Handling component

Mozilla FirefoxApplications & CMS

CVSS

NoneNot scored

ExploitationNo known exploitationNot in CISA KEV, which does not prove it is unexploitedCISA KEV

Exploit odds (EPSS)0.16%Chance of exploitation activity in the next 30 days, higher than 4% of CVEs. Scored 23 Oct 2026FIRST EPSS

Fixed inNone listedNo source names a fixed version. Check the vendor advisory below

Published13 Oct 2026Updated 13 Oct 2026CVE List

What fixes it

No source in this snapshot names a fixed version. The vendor advisories under References are the place to check.

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

Text from CVE List