All vulnerabilities
CVE-2026-100829

Firefox: Mitigation bypass in the DOM: Security component

Mozilla FirefoxApplications & CMS
Open in ThreatlineRecord JSON
CVSS
9.6Critical
ExploitationNo known exploitationNot in CISA KEV, which does not prove it is unexploitedCISA KEV
Exploit odds (EPSS)0.24%Chance of exploitation activity in the next 30 days, higher than 14% of CVEs. Scored 23 Oct 2026FIRST EPSS
Fixed inNone listedNo source names a fixed version. Check the vendor advisory below
Published29 Sep 2026Updated 1 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.

Description

Mitigation bypass in the DOM: Security component. This vulnerability was fixed in Firefox ESR 153.4, Thunderbird 157, Thunderbird 153.4, and Firefox 157.

Text from CVE List

Affected versions 4

  • Firefoxunaffected: 153.4 through 153.*CVE List
  • Firefoxunaffected: 157CVE List
  • Thunderbirdunaffected: 153.4 through 153.*CVE List
  • Thunderbirdunaffected: 157CVE List

References 5