CVE-2026-16390
published 2026-07-21CVE-2026-16390: Mitigation bypass in the Enterprise Policies component. This vulnerability was fixed in Firefox 153, Firefox ESR 140.13, Thunderbird 153, and Thunderbird…
PriorityP353critical9.1CVSS 3.1
AVNACLPRNUINSUCHIHAN
EPSS
0.32%
23.9th percentile
Mitigation bypass in the Enterprise Policies component. This vulnerability was fixed in Firefox 153, Firefox ESR 140.13, Thunderbird 153, and Thunderbird 140.13.
Affected
12 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 | thunderbird | < Thunderbird 153 | Thunderbird 153 |
| mozilla | thunderbird | < Thunderbird 140.13 | Thunderbird 140.13 |
| 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
nvdv3.19.1CRITICALCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N
vendor_redhat9.1CRITICAL
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Red Hat
firefox: thunderbird: Mitigation bypass in the Enterprise Policies component
vendor_redhat·2026-07-21·CVSS 9.1
CVE-2026-16390 [CRITICAL] firefox: thunderbird: Mitigation bypass in the Enterprise Policies component
firefox: thunderbird: Mitigation bypass in the Enterprise Policies component
A flaw was found in Firefox and Thunderbird. The Mozilla Foundation's Security Advisory describes the following issue:
Mitigation bypass in the Enterprise Policies 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
P
Mozilla
Mozilla Foundation Security Advisory 2026-70: CVE-2026-16390
vendor_mozilla
CVE-2026-16390 Mozilla Foundation Security Advisory 2026-70: CVE-2026-16390
Mozilla Foundation Security Advisory 2026-70
CVE: CVE-2026-16390
Product: Firefox ESR
Impact: high
Fixed in: Firefox ESR 140.13
Mozilla
Mozilla Foundation Security Advisory 2026-71: CVE-2026-16390
vendor_mozilla
CVE-2026-16390 Mozilla Foundation Security Advisory 2026-71: CVE-2026-16390
Mozilla Foundation Security Advisory 2026-71
CVE: CVE-2026-16390
Product: Thunderbird
Impact: high
Fixed in: Thunderbird 153
Mozilla
Mozilla Foundation Security Advisory 2026-68: CVE-2026-16390
vendor_mozilla
CVE-2026-16390 Mozilla Foundation Security Advisory 2026-68: CVE-2026-16390
Mozilla Foundation Security Advisory 2026-68
CVE: CVE-2026-16390
Product: Firefox
Impact: high
Fixed in: Firefox 153
Mozilla
Mozilla Foundation Security Advisory 2026-72: CVE-2026-16390
vendor_mozilla
CVE-2026-16390 Mozilla Foundation Security Advisory 2026-72: CVE-2026-16390
Mozilla Foundation Security Advisory 2026-72
CVE: CVE-2026-16390
Product: Thunderbird
Impact: high
Fixed in: Thunderbird 140.13
GHSA
Mitigation bypass in the Enterprise Policies component.
ghsa_unreviewed·2026-07-21
CVE-2026-16390 [CRITICAL] CWE-693 Mitigation bypass in the Enterprise Policies component.
Mitigation bypass in the Enterprise Policies component. This vulnerability was fixed in Firefox 153 and Firefox ESR 140.13.
No detection rules found.
No public exploits indexed.
2026-07-21
Published