CVE-2026-16371
published 2026-07-21CVE-2026-16371: Privilege escalation in the DOM: Navigation component. This vulnerability was fixed in Firefox 153, Firefox ESR 140.13, Thunderbird 153, Thunderbird 140.13…
PriorityP345high8.8CVSS 3.1
AVNACLPRNUIRSUCHIHAH
EPSS
0.30%
20.9th percentile
Privilege escalation in the DOM: Navigation component. This vulnerability was fixed in Firefox 153, Firefox ESR 140.13, Thunderbird 153, Thunderbird 140.13, Firefox ESR 140.15, and Thunderbird 140.15.
Affected
14 ranges
| Vendor | Product | Version range | Fixed in |
|---|---|---|---|
| mozilla | firefox | < Firefox 153 | Firefox 153 |
| mozilla | firefox | < 140.13.0 | 140.13.0 |
| mozilla | firefox | < 153.0.0 | 153.0.0 |
| mozilla | firefox | — | — |
| mozilla | firefox_esr | < Firefox ESR 140.13 | Firefox ESR 140.13 |
| mozilla | firefox_esr | < Firefox ESR 140.15 | Firefox ESR 140.15 |
| mozilla | thunderbird | < Thunderbird 140.15 | Thunderbird 140.15 |
| mozilla | thunderbird | < Thunderbird 140.13 | Thunderbird 140.13 |
| mozilla | thunderbird | < Thunderbird 153 | Thunderbird 153 |
| mozilla | thunderbird | < 140.13.0 | 140.13.0 |
| mozilla | thunderbird | — | — |
| mozilla | thunderbird | >= 141.0 < 153.0 | 153.0 |
| rhel10 | firefox-flatpak | — | — |
| rhel10 | thunderbird-flatpak | — | — |
CVSS provenance
nvdv3.18.8HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
vendor_redhat9.8CRITICAL
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Red Hat
firefox: thunderbird: Privilege escalation in the DOM: Navigation component
vendor_redhat·2026-07-21·CVSS 9.8
CVE-2026-16371 [CRITICAL] CWE-266 firefox: thunderbird: Privilege escalation in the DOM: Navigation component
firefox: thunderbird: Privilege escalation in the DOM: Navigation component
A flaw was found in Firefox and Thunderbird. The Mozilla Foundation's Security Advisory describes the following issue:
Privilege escalation in the DOM: Navigation 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) - Affected
Package: rhel10/firefox-flatpak (Red Hat Enterprise Linux 10) - Affected
Package: rhel10/thunderbird-flatpak (Red Hat Enterprise Linux 10) - Affected
Package: thunderbird (Red Hat Enterprise Linux 10) - Affected
Package: firefox (Red Hat Enterprise Linux 6) - Out of support scope
Package: thunderbird (Red Hat Enterprise Linux 6) - Out of support scope
Pac
Mozilla
Mozilla Foundation Security Advisory 2026-70: CVE-2026-16371
vendor_mozilla
CVE-2026-16371 Mozilla Foundation Security Advisory 2026-70: CVE-2026-16371
Mozilla Foundation Security Advisory 2026-70
CVE: CVE-2026-16371
Product: Firefox ESR
Impact: high
Fixed in: Firefox ESR 140.13
Mozilla
Mozilla Foundation Security Advisory 2026-84: CVE-2026-16371
vendor_mozilla·CVSS 8.8
CVE-2026-16371 [HIGH] Mozilla Foundation Security Advisory 2026-84: CVE-2026-16371
Mozilla Foundation Security Advisory 2026-84
CVE: CVE-2026-16371
Product: Firefox ESR
Impact: high
Fixed in: Firefox ESR 140.15
Mozilla
Mozilla Foundation Security Advisory 2026-87: CVE-2026-16371
vendor_mozilla·CVSS 8.8
CVE-2026-16371 [HIGH] Mozilla Foundation Security Advisory 2026-87: CVE-2026-16371
Mozilla Foundation Security Advisory 2026-87
CVE: CVE-2026-16371
Product: Thunderbird
Impact: high
Fixed in: Thunderbird 140.15
Mozilla
Mozilla Foundation Security Advisory 2026-72: CVE-2026-16371
vendor_mozilla
CVE-2026-16371 Mozilla Foundation Security Advisory 2026-72: CVE-2026-16371
Mozilla Foundation Security Advisory 2026-72
CVE: CVE-2026-16371
Product: Thunderbird
Impact: high
Fixed in: Thunderbird 140.13
Mozilla
Mozilla Foundation Security Advisory 2026-71: CVE-2026-16371
vendor_mozilla
CVE-2026-16371 Mozilla Foundation Security Advisory 2026-71: CVE-2026-16371
Mozilla Foundation Security Advisory 2026-71
CVE: CVE-2026-16371
Product: Thunderbird
Impact: high
Fixed in: Thunderbird 153
Mozilla
Mozilla Foundation Security Advisory 2026-68: CVE-2026-16371
vendor_mozilla
CVE-2026-16371 Mozilla Foundation Security Advisory 2026-68: CVE-2026-16371
Mozilla Foundation Security Advisory 2026-68
CVE: CVE-2026-16371
Product: Firefox
Impact: high
Fixed in: Firefox 153
VulDB
Mozilla Firefox up to 140.12/152 Navigation privileges management (EUVD-2026-46207 / Nessus ID 333348)
vuldb·2026-09-02·CVSS 8.8
CVE-2026-16371 [HIGH] Mozilla Firefox up to 140.12/152 Navigation privileges management (EUVD-2026-46207 / Nessus ID 333348)
A vulnerability, which was classified as critical, has been found in Mozilla Firefox up to 140.12/152. The impacted element is an unknown function of the component Navigation. Performing a manipulation results in improper privilege management.
This vulnerability is identified as CVE-2026-16371. The attack can be initiated remotely. There is not any exploit available.
It is advisable to upgrade the affected component.
GHSA
Privilege escalation in the DOM: Navigation component.
ghsa_unreviewed·2026-07-21
CVE-2026-16371 [CRITICAL] CWE-269 Privilege escalation in the DOM: Navigation component.
Privilege escalation in the DOM: Navigation component. This vulnerability was fixed in Firefox 153 and Firefox ESR 140.13.
No detection rules found.
No public exploits indexed.
https://bugzilla.mozilla.org/show_bug.cgi?id=2008369https://www.mozilla.org/security/advisories/mfsa2026-68/https://www.mozilla.org/security/advisories/mfsa2026-70/https://www.mozilla.org/security/advisories/mfsa2026-71/https://www.mozilla.org/security/advisories/mfsa2026-72/https://www.mozilla.org/security/advisories/mfsa2026-84/https://www.mozilla.org/security/advisories/mfsa2026-87/
2026-07-21
Published