CVE-2026-100801
High
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 159, Firefox ESR 153.6, Thunderbird 159, Thunderbird 153.6, Firefox 157, and Firefox ESR 140.17.
SeverityHigh
CVSS8.8
Exploit probability—
Product
Mozilla Firefox
PublishedSep 29, 2026
First seenSep 29, 2026
Weakness typeCWE-269Improper privilege management
How to fix
Update
- mozilla firefox140.17.0, 153.4.0, 157.0.0 or later
- mozilla thunderbird140.17.0, 153.4.0, 157.0 or later
Affected products
| Product | Affected versions | Fixed in |
|---|---|---|
| mozilla firefox | v < 140.17.0, 141.0 ≤ v < 153.4.0, 154.0.0 ≤ v < 157.0.0 | 140.17.0, 153.4.0, 157.0.0 |
| mozilla thunderbird | v < 140.17.0, 141.0 ≤ v < 153.4.0, 154.0 ≤ v < 157.0 | 140.17.0, 153.4.0, 157.0 |
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