CVE-2026-8389
HighPublished
JIT miscompilation in the JavaScript Engine: JIT component
- Published
- May 12, 2026
- Updated
- Jul 15, 2026
- Assigning CNA
- mozilla
- Evidence observed
- Aug 8, 2026
Primary CVSS
8.8/ 10High
nvd · CVSS 3.1
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H0.3%
Low · next 30 days
- Percentile
- 26.4%
- Model date
- Sep 21, 2026
EPSS is a statistical estimate, not a certainty or a measure of impact. Combine it with CVSS, KEV status, exposure and your environment.
Summary
JIT miscompilation in the JavaScript Engine: JIT component. This vulnerability was fixed in Firefox 150.0.3.
Sources
1Technical analysis and proof-of-concept exploit for CVE-2026-8389, a SpiderMonkey BaselineJIT type confusion vulnerability in Firefox, demonstrated with bytecode truncation and exception unwinding manipulation.
Responsible use
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