CVE-2026-8948

CRITICAL 9.1

Same-origin policy bypass in the DOM: Networking component

CVSS Score

9.1

EPSS Score

0.0%

EPSS Percentile

0th

Same-origin policy bypass in the DOM: Networking component. This vulnerability was fixed in Firefox 151 and Thunderbird 151.

Vendor	mozilla
Product	firefox
Ecosystems	Browser JavaScript
Industries	Technology
Published	May 19, 2026
Last Updated	Jun 30, 2026

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Affected Versions

Mozilla / Firefox

All versions affected

Mozilla / Thunderbird

All versions affected

References

NVD ↗ CVE.org ↗ EPSS Data ↗

bugzilla.mozilla.org: https://bugzilla.mozilla.org/show_bug.cgi?id=2038803 mozilla.org: https://www.mozilla.org/security/advisories/mfsa2026-46/ mozilla.org: https://www.mozilla.org/security/advisories/mfsa2026-50/ access.redhat.com: https://access.redhat.com/security/cve/CVE-2026-8948 bugzilla.redhat.com: https://bugzilla.redhat.com/show_bug.cgi?id=2479850 security.access.redhat.com: https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-8948.json

Credits

satyamasd