CVE-2026-74956
published 2026-08-18CVE-2026-74956: Same-origin policy bypass in the DOM: Service Workers component. This vulnerability was fixed in Firefox 154, Firefox ESR 153.1, Thunderbird 154, and…
PriorityP351critical9.1CVSS 3.1
AVNACLPRNUINSUCHIHAN
EPSS
0.28%
20.8th percentile
Same-origin policy bypass in the DOM: Service Workers component. This vulnerability was fixed in Firefox 154, Firefox ESR 153.1, Thunderbird 154, and Thunderbird 153.1.
Affected
8 ranges
| Vendor | Product | Version range | Fixed in |
|---|---|---|---|
| mozilla | firefox | < Firefox 154 | Firefox 154 |
| mozilla | firefox | < 153.1.0 | 153.1.0 |
| mozilla | firefox | < 154.0.0 | 154.0.0 |
| mozilla | firefox_esr | < Firefox ESR 153.1 | Firefox ESR 153.1 |
| mozilla | thunderbird | < Thunderbird 154 | Thunderbird 154 |
| mozilla | thunderbird | < Thunderbird 153.1 | Thunderbird 153.1 |
| mozilla | thunderbird | < 153.1.0 | 153.1.0 |
| mozilla | thunderbird | < 154.0 | 154.0 |
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: Same-origin policy bypass in the DOM: Service Workers component
vendor_redhat·2026-08-18·CVSS 9.1
CVE-2026-74956 [CRITICAL] CWE-346 firefox: Same-origin policy bypass in the DOM: Service Workers component
firefox: Same-origin policy bypass in the DOM: Service Workers component
A flaw was found in Firefox. The Mozilla Foundation's Security Advisory describes the following issue:
Same-origin policy bypass in the DOM: Service 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: firefox (Red Hat Enterprise Linux 6) - Not affected
Package: firefox (Red Hat Enterprise Linux 7) - Not affected
Package: firefox (Red Hat Enterprise Linux 8) - Not affected
Package: firefox (Red Hat Enterprise Linux 9) - Not affected
Mozilla
Mozilla Foundation Security Advisory 2026-78: CVE-2026-74956
vendor_mozilla
CVE-2026-74956 Mozilla Foundation Security Advisory 2026-78: CVE-2026-74956
Mozilla Foundation Security Advisory 2026-78
CVE: CVE-2026-74956
Product: Thunderbird
Impact: high
Fixed in: Thunderbird 154
Mozilla
Mozilla Foundation Security Advisory 2026-77: CVE-2026-74956
vendor_mozilla
CVE-2026-74956 Mozilla Foundation Security Advisory 2026-77: CVE-2026-74956
Mozilla Foundation Security Advisory 2026-77
CVE: CVE-2026-74956
Product: Firefox ESR
Impact: high
Fixed in: Firefox ESR 153.1
Mozilla
Mozilla Foundation Security Advisory 2026-80: CVE-2026-74956
vendor_mozilla
CVE-2026-74956 Mozilla Foundation Security Advisory 2026-80: CVE-2026-74956
Mozilla Foundation Security Advisory 2026-80
CVE: CVE-2026-74956
Product: Thunderbird
Impact: high
Fixed in: Thunderbird 153.1
Mozilla
Mozilla Foundation Security Advisory 2026-74: CVE-2026-74956
vendor_mozilla
CVE-2026-74956 Mozilla Foundation Security Advisory 2026-74: CVE-2026-74956
Mozilla Foundation Security Advisory 2026-74
CVE: CVE-2026-74956
Product: Firefox
Impact: high
Fixed in: Firefox 154
GHSA
Same-origin policy bypass in the DOM: Service Workers component.
ghsa_unreviewed·2026-08-18
CVE-2026-74956 [CRITICAL] CWE-843 Same-origin policy bypass in the DOM: Service Workers component.
Same-origin policy bypass in the DOM: Service Workers component. This vulnerability was fixed in Firefox 154 and Firefox ESR 153.1.
No detection rules found.
No public exploits indexed.
2026-08-18
Published