CVE-2026-100801
Thunderbird: Privilege escalation in the DLL Services component
Mozilla Thunderbird
CVSS
8.8HighExploitationNo known exploitationNot in CISA KEV, which does not prove it is unexploitedCISA KEV
Exploit odds (EPSS)0.23%Chance of exploitation activity in the next 30 days, higher than 13% of CVEs. Scored 23 Oct 2026FIRST EPSS
Fixed inNone listedNo source names a fixed version. Check the vendor advisory below
What fixes it
No source in this snapshot names a fixed version. The vendor advisories under References are the place to check.
Description
Privilege escalation in the DLL Services component. This vulnerability was fixed in Firefox ESR 153.4, Thunderbird 157, Thunderbird 140.17, Thunderbird 153.4, Firefox 157, and Firefox ESR 140.17.
Text from CVE List
Affected versions 6
- Thunderbirdunaffected: 140.17 through 140.*CVE List
- Thunderbirdunaffected: 153.4 through 153.*CVE List
- Thunderbirdunaffected: 157CVE List
- Firefoxunaffected: 140.17 through 140.*CVE List
- Firefoxunaffected: 153.4 through 153.*CVE List
- Firefoxunaffected: 157CVE List
References 7
- mozilla.org/security/advisories/mfsa2026-100/Advisoryvia CVE List
- mozilla.org/security/advisories/mfsa2026-101/Advisoryvia CVE List
- mozilla.org/security/advisories/mfsa2026-102/Advisoryvia CVE List
- mozilla.org/security/advisories/mfsa2026-103/Advisoryvia CVE List
- mozilla.org/security/advisories/mfsa2026-97/Advisoryvia CVE List
- mozilla.org/security/advisories/mfsa2026-99/Advisoryvia CVE List
- bugzilla.mozilla.org/show_bug.cgi?id=2057112Referencevia CVE List