CVE-2026-109772

Firefox: Same-origin policy bypass in the DevTools 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.

Same-origin policy bypass in the DevTools component. This vulnerability was fixed in Firefox 158 and Thunderbird 158.

Text from CVE List