CVE-2026-8955
HIGHCVSS 8.8/10EPSS 0.39%
Last modified
CVE-2026-8955 is a high-severity vulnerability rated 8.8/10 on the CVSS scale. Privilege escalation in the DOM: Workers component. This vulnerability was fixed in Firefox 151, Firefox ESR 140.11, Thunderbird 151, and Thunderbird 140.11.. EPSS estimates a 0.39% chance of exploitation in the next 30 days.
Description
Privilege escalation in the DOM: Workers component. This vulnerability was fixed in Firefox 151, Firefox ESR 140.11, Thunderbird 151, and Thunderbird 140.11.
Metrics
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
Weakness Enumeration
Affected Software
| Vendor | Product | Versions |
|---|---|---|
| Mozilla | Firefox | < 140.11.0 |
| Mozilla | Firefox | < 151.0.0 |
| Mozilla | Thunderbird | < 140.11 |
| Mozilla | Thunderbird | < 151.0.0 |
References
- https://bugzilla.mozilla.org/show_bug.cgi?id=2031064Permissions Required
- https://www.mozilla.org/security/advisories/mfsa2026-46/Vendor Advisory
- https://www.mozilla.org/security/advisories/mfsa2026-48/Vendor Advisory
- https://www.mozilla.org/security/advisories/mfsa2026-50/Vendor Advisory
- https://www.mozilla.org/security/advisories/mfsa2026-51/Vendor Advisory
Timeline
- Published
- Last Modified
- Status
- Modified
Frequently Asked Questions
What is CVE-2026-8955?
Privilege escalation in the DOM: Workers component. This vulnerability was fixed in Firefox 151, Firefox ESR 140.11, Thunderbird 151, and Thunderbird 140.11.
How severe is CVE-2026-8955?
CVE-2026-8955 has a CVSS score of 8.8/10 (HIGH severity). The EPSS model estimates a 0.39% probability of exploitation in the next 30 days.
How do I fix CVE-2026-8955?
Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.
Are you affected by CVE-2026-8955?
Run a free Strix scan to check your systems for this vulnerability.
Scan your code nowSource: NVD / NIST