CVE-2026-16365
published 2026-07-21CVE-2026-16365: Privilege escalation in the DOM: Workers component. This vulnerability was fixed in Firefox 153, Thunderbird 153, Firefox ESR 140.15, and Thunderbird 140.15.
PriorityP345high8.8CVSS 3.1
AVNACLPRNUIRSUCHIHAH
EPSS
0.28%
18.9th percentile
Privilege escalation in the DOM: Workers component. This vulnerability was fixed in Firefox 153, Thunderbird 153, Firefox ESR 140.15, and Thunderbird 140.15.
Affected
6 ranges
| Vendor | Product | Version range | Fixed in |
|---|---|---|---|
| mozilla | firefox | < Firefox 153 | Firefox 153 |
| mozilla | firefox | < 153.0.0 | 153.0.0 |
| mozilla | firefox_esr | < Firefox ESR 140.15 | Firefox ESR 140.15 |
| mozilla | thunderbird | < Thunderbird 140.15 | Thunderbird 140.15 |
| mozilla | thunderbird | < Thunderbird 153 | Thunderbird 153 |
| mozilla | thunderbird | < 153.0 | 153.0 |
CVSS provenance
nvdv3.18.8HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
vendor_redhat8.8HIGH
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Red Hat
firefox: thunderbird: Privilege escalation in the DOM: Workers component
vendor_redhat·2026-07-21·CVSS 8.8
CVE-2026-16365 [HIGH] CWE-266 firefox: thunderbird: Privilege escalation in the DOM: Workers component
firefox: thunderbird: Privilege escalation in the DOM: Workers component
A flaw was found in Firefox and Thunderbird. The Mozilla Foundation's Security Advisory describes the following issue:
Privilege escalation in the DOM: Workers component
Statement: Red Hat Product Security rates the severity of this flaw as determined by the Mozilla Foundation Security Advisory.
Package: firefox (Red Hat Enterprise Linux 10) - Not affected
Package: rhel10/firefox-flatpak (Red Hat Enterprise Linux 10) - Not affected
Package: rhel10/thunderbird-flatpak (Red Hat Enterprise Linux 10) - Not affected
Package: thunderbird (Red Hat Enterprise Linux 10) - Not affected
Package: firefox (Red Hat Enterprise Linux 6) - Not affected
Package: thunderbird (Red Hat Enterprise Linux 6) - Not affected
Package:
Mozilla
Mozilla Foundation Security Advisory 2026-87: CVE-2026-16365
vendor_mozilla·CVSS 8.8
CVE-2026-16365 [HIGH] Mozilla Foundation Security Advisory 2026-87: CVE-2026-16365
Mozilla Foundation Security Advisory 2026-87
CVE: CVE-2026-16365
Product: Thunderbird
Impact: high
Fixed in: Thunderbird 140.15
Mozilla
Mozilla Foundation Security Advisory 2026-68: CVE-2026-16365
vendor_mozilla
CVE-2026-16365 Mozilla Foundation Security Advisory 2026-68: CVE-2026-16365
Mozilla Foundation Security Advisory 2026-68
CVE: CVE-2026-16365
Product: Firefox
Impact: high
Fixed in: Firefox 153
Mozilla
Mozilla Foundation Security Advisory 2026-84: CVE-2026-16365
vendor_mozilla·CVSS 8.8
CVE-2026-16365 [HIGH] Mozilla Foundation Security Advisory 2026-84: CVE-2026-16365
Mozilla Foundation Security Advisory 2026-84
CVE: CVE-2026-16365
Product: Firefox ESR
Impact: high
Fixed in: Firefox ESR 140.15
Mozilla
Mozilla Foundation Security Advisory 2026-71: CVE-2026-16365
vendor_mozilla
CVE-2026-16365 Mozilla Foundation Security Advisory 2026-71: CVE-2026-16365
Mozilla Foundation Security Advisory 2026-71
CVE: CVE-2026-16365
Product: Thunderbird
Impact: high
Fixed in: Thunderbird 153
VulDB
Mozilla Firefox up to 152 Workers privileges management (CNNVD-2026-99451170)
vuldb·2026-09-02·CVSS 8.8
CVE-2026-16365 [HIGH] Mozilla Firefox up to 152 Workers privileges management (CNNVD-2026-99451170)
A vulnerability was found in Mozilla Firefox up to 152. It has been declared as critical. This impacts an unknown function of the component Workers. The manipulation results in improper privilege management.
This vulnerability is reported as CVE-2026-16365. The attack can be launched remotely. No exploit exists.
It is recommended to upgrade the affected component.
GHSA
Privilege escalation in the DOM: Workers component.
ghsa_unreviewed·2026-07-21
CVE-2026-16365 [CRITICAL] CWE-269 Privilege escalation in the DOM: Workers component.
Privilege escalation in the DOM: Workers component. This vulnerability was fixed in Firefox 153.
No detection rules found.
No public exploits indexed.
2026-07-21
Published