CVE-2026-16365CWE-269CWE-284broken-access-controlprivilege-escalation

CVE-2026-16365

High · published July 21, 2026

CVSS v3.1

8.8

EPSS

Percentile

19.2

In the wild

Unconfirmed

What it is

Privilege escalation in the DOM: Workers component. This vulnerability was fixed in Firefox 153, Thunderbird 153, Firefox ESR 140.15, and Thunderbird 140.15.

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: 0.00278 · 19.2th percentile
Weaknesses: CWE-269 · Improper Privilege Management; CWE-284 · Improper Access Control
Published: 2026-07-21T17:17Z

Affected products (2)

Product	Versions	Fixed in
mozilla/firefox	< 153.0.0	153.0.0
mozilla/thunderbird	< 153.0	153.0

References (5)

https://bugzilla.mozilla.org/show_bug.cgi?id=2049149 · [email protected]https://www.mozilla.org/security/advisories/mfsa2026-68/ · [email protected]https://www.mozilla.org/security/advisories/mfsa2026-71/ · [email protected]https://www.mozilla.org/security/advisories/mfsa2026-84/ · [email protected]https://www.mozilla.org/security/advisories/mfsa2026-87/ · [email protected]

EPSS history

Timeline

21 JUL 12:37Z
Privilege escalation in the DOM: Workers component
cvelistv5