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Critical 9.1Published May 19, 2026
CVE-2026-8948Same-origin policy bypass in the DOM: Networking component
Updated under an hour ago ()
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It affects Mozilla Firefox and 2 other products. Add what you run to find out whether that includes you.
No exploitation reported and no EPSS estimate yet.
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Same-origin policy bypass in the DOM: Networking component. This vulnerability was fixed in Firefox 151 and Thunderbird 151.
- CVSS
- 9.1 CRITICAL (v3.1, CISA ADP)CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N
- Weakness (CWE)
- CWE-942, CWE-79
- Known exploited
- Not in CISA's KEV catalog
- EPSS (exploitation in the next 30 days)
- Not loaded for this CVE
- Assigned by
- mozilla
- NVD analysis
- Modified
- Record last updated
- Jul 14, 2026
- First seen by InfoSec Signals
- Oct 9, 2026
Affected products
Mozilla Firefox mozilla:firefox (from the name) | from 151 not affected | CNA record |
Mozilla Thunderbird mozilla:thunderbird (from the name) | from 151 not affected | CNA record |
Red Hat Red Hat Enterprise Linux 10 redhat:enterprise_linux | 10 | CISA ADP |
mozilla firefox mozilla:firefox | before 151.0.0 | NVD |
mozilla thunderbird mozilla:thunderbird | before 151.0.0 | NVD |
References
- https://bugzilla.mozilla.org/show_bug.cgi?id=2038803permissions-required
- https://www.mozilla.org/security/advisories/mfsa2026-46/vendor-advisory
- https://www.mozilla.org/security/advisories/mfsa2026-50/vendor-advisory
- https://access.redhat.com/security/cve/CVE-2026-8948
- https://bugzilla.redhat.com/show_bug.cgi?id=2479850
- https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-8948.json
The CVE record on cve.org NVD's entry
The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.