VulnerabilityModified
CVE-2026-16365
Privilege escalation in the DOM: Workers component.
HIGH 8.8EPSS 0.28%
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (0.28%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
Description
Privilege escalation in the DOM: Workers component. This vulnerability was fixed in Firefox 153, Thunderbird 153, Firefox ESR 140.15, and Thunderbird 140.15.
- CVSS 3.1
- 8.8 HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
- EPSS
- 0.28% probability · 20th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-269, CWE-284
- Affected
- mozilla/firefox · mozilla/thunderbird
- Source
- security@mozilla.org
References
- https://bugzilla.mozilla.org/show_bug.cgi?id=2049149Permissions Required
- https://www.mozilla.org/security/advisories/mfsa2026-68/Vendor Advisory
- https://www.mozilla.org/security/advisories/mfsa2026-71/Vendor Advisory
- https://www.mozilla.org/security/advisories/mfsa2026-84/
- https://www.mozilla.org/security/advisories/mfsa2026-87/
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.