CVE-2026-16355
Received Received - Intake

JIT Miscompilation in Firefox JavaScript Engine

Publication date: 2026-07-21

Last updated on: 2026-07-21

Assigner: Mozilla Corporation

Description
JIT miscompilation in the JavaScript Engine: JIT component. This vulnerability was fixed in Firefox 153, Firefox ESR 115.38, and Firefox ESR 140.13.

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Meta Information

Published
2026-07-21
Last Modified
2026-07-21
Generated
2026-07-21
AI Q&A
2026-07-21
EPSS Evaluated
N/A
NVD
CVE-2026-16355
EUVD
EUVD-2026-46203

Affected Vendors & Products

Showing 5 associated CPEs
Vendor Product Version / Range
mozilla firefox to 153 (inc)
mozilla firefox_esr to 115.38 (inc)
mozilla firefox_esr to 140.13 (inc)
mozilla firefox 153
mozilla firefox esr

Helpful Resources

Exploitability

CWE
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CWE ID Description
CWE-UNKNOWN

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Executive Summary

This is a JIT miscompilation vulnerability in Firefox's JavaScript Engine. JIT stands for Just-In-Time compilation, which speeds up JavaScript execution. A miscompilation here could lead to incorrect code generation, potentially causing crashes or unexpected behavior in the browser.

Detection Guidance

This vulnerability is fixed in Firefox 153, Firefox ESR 115.38, and Firefox ESR 140.13. Check your Firefox version with 'firefox --version' or 'about:support' in the browser. If your version is older, the system is vulnerable.

Impact Analysis

If exploited, this vulnerability could allow attackers to execute arbitrary code on your system, crash your browser, or bypass security mechanisms. Users running unpatched versions of Firefox may be at risk of malicious websites leveraging this flaw.

Compliance Impact

The provided CVE data does not specify how this vulnerability impacts compliance with standards like GDPR or HIPAA. Without additional context on data exposure or processing implications, its effect on compliance cannot be determined.

Mitigation Strategies

Update Firefox to version 153 or later, Firefox ESR 115.38 or later, or Firefox ESR 140.13 or later. Disable JavaScript if not required or use a browser with JIT disabled as a temporary workaround.

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