CVE-2026-74976
Received Received - Intake

JIT Miscompilation in Firefox JavaScript Engine

Publication date: 2026-08-18

Last updated on: 2026-08-18

Assigner: Mozilla Corporation

Description
JIT miscompilation in the JavaScript Engine: JIT component. This vulnerability was fixed in Firefox 154, Firefox ESR 140.14, and Firefox ESR 153.1.

CVSS Scores

EPSS Scores

Probability:
Percentile:

Meta Information

Published
2026-08-18
Last Modified
2026-08-18
Generated
2026-08-18
AI Q&A
2026-08-18
EPSS Evaluated
N/A
NVD
CVE-2026-74976
EUVD
EUVD-2026-60670

Affected Vendors & Products

Showing 6 associated CPEs
Vendor Product Version / Range
mozilla firefox to 154 (inc)
mozilla firefox_esr to 140.14 (inc)
mozilla firefox_esr to 153.1 (inc)
mozilla firefox 154
mozilla firefox_esr 140.14
mozilla firefox_esr 153.1

Helpful Resources

Exploitability

CWE
CWE Icon
KEV
KEV Icon
CWE ID Description
CWE-UNKNOWN

Attack-Flow Graph

AI Quick Actions

Instant insights powered by AI
Executive Summary

This is a JIT miscompilation vulnerability in Firefox's JavaScript Engine. It occurs when the Just-In-Time compiler incorrectly translates JavaScript code, potentially leading to memory corruption or arbitrary code execution. The issue was patched in Firefox 154, Firefox ESR 140.14, and Firefox ESR 153.1.

Detection Guidance

This vulnerability is specific to Firefox and Firefox ESR versions affected by JIT miscompilation. Detection involves checking installed versions of Firefox or Firefox ESR against the fixed versions (Firefox 154, Firefox ESR 140.14, Firefox ESR 153.1). Use commands like 'firefox --version' or 'firefox-esr --version' to check versions. If versions are below the fixed releases, the system is vulnerable.

Impact Analysis

If exploited, this vulnerability could allow attackers to execute arbitrary code on your system, crash the browser, or bypass security mechanisms. Users running unpatched versions of Firefox or Firefox ESR are at risk.

Compliance Impact

The provided CVE data does not specify how this vulnerability impacts compliance with standards like GDPR or HIPAA. The description only mentions a JIT miscompilation issue in Firefox without details on data exposure or regulatory implications.

Mitigation Strategies

Update Firefox to version 154 or later, Firefox ESR to version 140.14 or later, or Firefox ESR to version 153.1 or later to address the JIT miscompilation vulnerability.

Chat Assistant

Ask questions about this CVE
Hi! I’m here to help you understand CVE-2026-74976. Ask me anything about the vulnerability, its impact, or mitigation strategies.
0/70

EPSS Chart