CVE-2026-8956
Critical
Published: 19 May 2026
Published
19 May 2026
Modified
20 May 2026
KEV Added
—
Patch
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CVSS Score
9.8
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
EPSS Score
0.0005
14.2th percentile
Risk Priority
20
60% EPSS · 20% KEV · 20% CVSS
Summary
CVE-2026-8956 is a critical-severity Integer Overflow or Wraparound (CWE-190) vulnerability in Mozilla Firefox. Its CVSS base score is 9.8 (Critical).
Operationally, ranked at the 14.2th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.
NVD Description
Integer overflow in the Networking: JAR component. This vulnerability was fixed in Firefox 151, Firefox ESR 140.11, Thunderbird 151, and Thunderbird 140.11.
Deeper analysisAI
Automated synthesis unavailable for this CVE.
Details
- CWE(s)
Affected Products
mozilla
firefox
≤ 140.11.0 · ≤ 151.0.0
mozilla
thunderbird
≤ 140.11 · ≤ 151.0.0