by Kastro
Paper/Archive/CVE-2026-8950

CVE-2026-8950

Mozilla Firefox — Same-origin policy bypass in the Networking: HTTP component

EPSS 0.2%CVSS 9.3
critical.is priorityof 100
30
CVSS 9.3 (ADP)9.3 / 10 × 3027.9Not in CISA KEV+300.0EPSS percentile 9.1.091 × 201.8No public exploit+100.0SSVC exploitation: none+100.0
Description · from the CVE record

Same-origin policy bypass in the Networking: HTTP component. This vulnerability was fixed in Firefox 151, Firefox ESR 140.11, Thunderbird 151, and Thunderbird 140.11.

Affected

ProductAffectedFixed inSource
Firefoxsee advisory140.11CNA
Thunderbirdsee advisory140.11CNA

Scores by source

CISA ADP9.3CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:N
CISA ADPSSVCExploitation: none · Automatable: no · Technical impact: partial

References

refbugzilla.mozilla.org/show_bug.cgi?id=1965430refmozilla.org/security/advisories/mfsa2026-46refmozilla.org/security/advisories/mfsa2026-48refmozilla.org/security/advisories/mfsa2026-50refmozilla.org/security/advisories/mfsa2026-51