CVE-2026-74939
published 2026-08-18CVE-2026-74939: Privilege escalation in the DOM: Navigation component. This vulnerability was fixed in Firefox 154, Firefox ESR 115.39, Firefox ESR 140.14, Firefox ESR 153.1…
PriorityP346high8.8CVSS 3.1
AVNACLPRNUIRSUCHIHAH
EPSS
0.30%
22.6th percentile
Privilege escalation in the DOM: Navigation component. This vulnerability was fixed in Firefox 154, Firefox ESR 115.39, Firefox ESR 140.14, Firefox ESR 153.1, Thunderbird 154, Thunderbird 140.14, and Thunderbird 153.1.
Affected
16 ranges
| Vendor | Product | Version range | Fixed in |
|---|---|---|---|
| mozilla | firefox | < Firefox 154 | Firefox 154 |
| mozilla | firefox | < 115.39.0 | 115.39.0 |
| mozilla | firefox | — | — |
| mozilla | firefox | >= 116.0 < 140.14.0 | 140.14.0 |
| mozilla | firefox | >= 141.0 < 153.1.0 | 153.1.0 |
| mozilla | firefox_esr | < Firefox ESR 140.14 | Firefox ESR 140.14 |
| mozilla | firefox_esr | < Firefox ESR 115.39 | Firefox ESR 115.39 |
| mozilla | firefox_esr | < Firefox ESR 153.1 | Firefox ESR 153.1 |
| mozilla | thunderbird | < Thunderbird 153.1 | Thunderbird 153.1 |
| mozilla | thunderbird | < Thunderbird 140.14 | Thunderbird 140.14 |
| mozilla | thunderbird | < Thunderbird 154 | Thunderbird 154 |
| mozilla | thunderbird | < 140.14.0 | 140.14.0 |
| mozilla | thunderbird | — | — |
| mozilla | thunderbird | >= 141.0 < 153.1.0 | 153.1.0 |
| 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_redhat8.8HIGH
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Red Hat
firefox: thunderbird: Privilege escalation in the DOM: Navigation component
vendor_redhat·2026-08-18·CVSS 8.8
CVE-2026-74939 [HIGH] CWE-266 firefox: thunderbird: Privilege escalation in the DOM: Navigation component
firefox: thunderbird: Privilege escalation in the DOM: Navigation component
Privilege escalation in the DOM: Navigation component. This vulnerability was fixed in Firefox 154, Firefox ESR 115.39, Firefox ESR 140.14, Firefox ESR 153.1, Thunderbird 154, Thunderbird 140.14, and Thunderbird 153.1.
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) -
Mozilla
Mozilla Foundation Security Advisory 2026-80: CVE-2026-74939
vendor_mozilla
CVE-2026-74939 Mozilla Foundation Security Advisory 2026-80: CVE-2026-74939
Mozilla Foundation Security Advisory 2026-80
CVE: CVE-2026-74939
Product: Thunderbird
Impact: high
Fixed in: Thunderbird 153.1
Mozilla
Mozilla Foundation Security Advisory 2026-74: CVE-2026-74939
vendor_mozilla
CVE-2026-74939 Mozilla Foundation Security Advisory 2026-74: CVE-2026-74939
Mozilla Foundation Security Advisory 2026-74
CVE: CVE-2026-74939
Product: Firefox
Impact: high
Fixed in: Firefox 154
Mozilla
Mozilla Foundation Security Advisory 2026-79: CVE-2026-74939
vendor_mozilla
CVE-2026-74939 Mozilla Foundation Security Advisory 2026-79: CVE-2026-74939
Mozilla Foundation Security Advisory 2026-79
CVE: CVE-2026-74939
Product: Thunderbird
Impact: high
Fixed in: Thunderbird 140.14
Mozilla
Mozilla Foundation Security Advisory 2026-76: CVE-2026-74939
vendor_mozilla
CVE-2026-74939 Mozilla Foundation Security Advisory 2026-76: CVE-2026-74939
Mozilla Foundation Security Advisory 2026-76
CVE: CVE-2026-74939
Product: Firefox ESR
Impact: high
Fixed in: Firefox ESR 140.14
Mozilla
Mozilla Foundation Security Advisory 2026-78: CVE-2026-74939
vendor_mozilla
CVE-2026-74939 Mozilla Foundation Security Advisory 2026-78: CVE-2026-74939
Mozilla Foundation Security Advisory 2026-78
CVE: CVE-2026-74939
Product: Thunderbird
Impact: high
Fixed in: Thunderbird 154
Mozilla
Mozilla Foundation Security Advisory 2026-75: CVE-2026-74939
vendor_mozilla
CVE-2026-74939 Mozilla Foundation Security Advisory 2026-75: CVE-2026-74939
Mozilla Foundation Security Advisory 2026-75
CVE: CVE-2026-74939
Product: Firefox ESR
Impact: high
Fixed in: Firefox ESR 115.39
Mozilla
Mozilla Foundation Security Advisory 2026-77: CVE-2026-74939
vendor_mozilla
CVE-2026-74939 Mozilla Foundation Security Advisory 2026-77: CVE-2026-74939
Mozilla Foundation Security Advisory 2026-77
CVE: CVE-2026-74939
Product: Firefox ESR
Impact: high
Fixed in: Firefox ESR 153.1
VulDB
Mozilla Firefox up to 115.38/140.13/153/153.0 Navigation privileges management (Nessus ID 337938)
vuldb·2026-08-23·CVSS 8.8
CVE-2026-74939 [HIGH] Mozilla Firefox up to 115.38/140.13/153/153.0 Navigation privileges management (Nessus ID 337938)
A vulnerability labeled as critical has been found in Mozilla Firefox up to 115.38/140.13/153/153.0. Affected by this issue is some unknown functionality of the component Navigation Component. The manipulation results in improper privilege management.
This vulnerability is known as CVE-2026-74939. It is possible to launch the attack remotely. No exploit is available.
The affected component should be upgraded.
GHSA
Privilege escalation in the DOM: Navigation component.
ghsa_unreviewed·2026-08-18
CVE-2026-74939 [HIGH] CWE-269 Privilege escalation in the DOM: Navigation component.
Privilege escalation in the DOM: Navigation component. This vulnerability was fixed in Firefox 154, Firefox ESR 115.39, Firefox ESR 140.14, and Firefox ESR 153.1.
No detection rules found.
No public exploits indexed.
https://bugzilla.mozilla.org/show_bug.cgi?id=2054416https://www.mozilla.org/security/advisories/mfsa2026-74/https://www.mozilla.org/security/advisories/mfsa2026-75/https://www.mozilla.org/security/advisories/mfsa2026-76/https://www.mozilla.org/security/advisories/mfsa2026-77/https://www.mozilla.org/security/advisories/mfsa2026-78/https://www.mozilla.org/security/advisories/mfsa2026-79/https://www.mozilla.org/security/advisories/mfsa2026-80/
2026-08-18
Published