CVE-2026-8948
published 2026-05-19CVE-2026-8948: Same-origin policy bypass in the DOM: Networking component. This vulnerability was fixed in Firefox 151 and Thunderbird 151.
PriorityP349critical9.1CVSS 3.1
AVNACLPRNUINSUCHIHAN
EPSS
0.42%
34.1th percentile
Same-origin policy bypass in the DOM: Networking component. This vulnerability was fixed in Firefox 151 and Thunderbird 151.
Affected
4 ranges
| Vendor | Product | Version range | Fixed in |
|---|---|---|---|
| mozilla | firefox | < Firefox 151 | Firefox 151 |
| mozilla | firefox | < 151.0.0 | 151.0.0 |
| mozilla | thunderbird | < Thunderbird 151 | Thunderbird 151 |
| mozilla | thunderbird | < 151.0.0 | 151.0.0 |
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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GHSA
GHSA-j9gx-gpjh-cwc4: Same-origin policy bypass in the DOM: Networking component
ghsa_unreviewed·2026-05-19
CVE-2026-8948 [CRITICAL] CWE-942 GHSA-j9gx-gpjh-cwc4: Same-origin policy bypass in the DOM: Networking component
Same-origin policy bypass in the DOM: Networking component. This vulnerability was fixed in Firefox 151.
VulDB
Mozilla Firefox up to 150 Networking cross-domain policy
vuldb·2026-05-19·CVSS 9.1
CVE-2026-8948 [CRITICAL] Mozilla Firefox up to 150 Networking cross-domain policy
A vulnerability was found in Mozilla Firefox up to 150. It has been rated as problematic. This issue affects some unknown processing of the component Networking Component. Performing a manipulation results in permissive cross-domain policy with untrusted domains.
This vulnerability is known as CVE-2026-8948. Remote exploitation of the attack is possible. No exploit is available.
Upgrading the affected component is advised.
Red Hat
firefox: thunderbird: Same-origin policy bypass in the DOM: Networking component
vendor_redhat·2026-05-19·CVSS 9.1
CVE-2026-8948 [CRITICAL] CWE-79 firefox: thunderbird: Same-origin policy bypass in the DOM: Networking component
firefox: thunderbird: Same-origin policy bypass in the DOM: Networking component
Same-origin policy bypass in the DOM: Networking component. This vulnerability was fixed in Firefox 151 and Thunderbird 151.
A flaw was found in Firefox and Thunderbird. The Mozilla Foundation's Security Advisory describes the following issue:
Same-origin policy bypass in the DOM: Networking 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 affec
Mozilla
Mozilla Foundation Security Advisory 2026-46: CVE-2026-8948
vendor_mozilla·CVSS 9.1
CVE-2026-8948 [CRITICAL] Mozilla Foundation Security Advisory 2026-46: CVE-2026-8948
Mozilla Foundation Security Advisory 2026-46
CVE: CVE-2026-8948
Product: Firefox
Impact: high
Fixed in: Firefox 151
Mozilla
Mozilla Foundation Security Advisory 2026-50: CVE-2026-8948
vendor_mozilla·CVSS 9.1
CVE-2026-8948 [CRITICAL] Mozilla Foundation Security Advisory 2026-50: CVE-2026-8948
Mozilla Foundation Security Advisory 2026-50
CVE: CVE-2026-8948
Product: Thunderbird
Impact: high
Fixed in: Thunderbird 151
No detection rules found.
No public exploits indexed.
https://bugzilla.mozilla.org/show_bug.cgi?id=2038803https://www.mozilla.org/security/advisories/mfsa2026-46/https://www.mozilla.org/security/advisories/mfsa2026-50/https://access.redhat.com/security/cve/CVE-2026-8948https://bugzilla.redhat.com/show_bug.cgi?id=2479850https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-8948.json
2026-05-19
Published