CVE-2026-8955CWE-269privilege-escalation

CVE-2026-8955

High · published May 19, 2026

CVSS v3.1
8.8
EPSS
0%
Percentile
34.7
In the wild
Unconfirmed
What it is

Privilege escalation in the DOM: Workers component. This vulnerability was fixed in Firefox 151, Firefox ESR 140.11, Thunderbird 151, and Thunderbird 140.11.

The record
Technical detail
CVSS v3.1
8.8 · HIGH
Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
CVSS v4.0
Not supplied
EPSS
0.00415 · 34.7th percentile
Weakness
CWE-269 · Improper Privilege Management
Published
2026-05-19T18:16Z
Affected products (4)
ProductVersionsFixed in
mozilla/firefox< 140.11.0140.11.0
mozilla/firefox< 151.0.0151.0.0
mozilla/thunderbird< 140.11140.11
mozilla/thunderbird< 151.0.0151.0.0
References (5)
https://bugzilla.mozilla.org/show_bug.cgi?id=2031064 · [email protected]https://www.mozilla.org/security/advisories/mfsa2026-46/ · [email protected]https://www.mozilla.org/security/advisories/mfsa2026-48/ · [email protected]https://www.mozilla.org/security/advisories/mfsa2026-50/ · [email protected]https://www.mozilla.org/security/advisories/mfsa2026-51/ · [email protected]
EPSS history
Timeline
  • 19 MAY 12:29Z
    Privilege escalation in the DOM: Workers component
    cvelistv5