CVE-2026-4698: Vulnerability in Mozilla Firefox
JIT miscompilation in the JavaScript Engine: JIT component. This vulnerability was fixed in Firefox 149, Firefox ESR 115.34, Firefox ESR 140.9, Thunderbird 149, and Thunderbird 140.9.
AI Analysis
Technical Summary
CVE-2026-4698 involves a Just-In-Time (JIT) miscompilation issue within the JavaScript Engine's JIT component in Mozilla Firefox. This vulnerability was identified and reported by security researchers and fixed in Firefox 149, Firefox ESR 115.34, and Firefox ESR 140.9. The CVSS v3.1 score is 8.8, indicating a high severity with network attack vector, low attack complexity, no privileges required, user interaction required, and impacts to confidentiality, integrity, and availability. The vendor advisories confirm the fix and provide detailed references to the underlying bugs. No known exploits in the wild have been reported at this time.
Potential Impact
Successful exploitation of this vulnerability could allow an attacker to execute arbitrary code or cause significant disruption to the affected Firefox browser, impacting confidentiality, integrity, and availability. The high CVSS score reflects the critical nature of the vulnerability in the JavaScript engine's JIT compilation process.
Mitigation Recommendations
Mozilla has released official fixes for this vulnerability in Firefox 149, Firefox ESR 115.34, and Firefox ESR 140.9. Users and administrators should update affected Firefox installations to these versions or later to mitigate the risk. No additional mitigation steps are required beyond applying the official patches.
CVE-2026-4698: Vulnerability in Mozilla Firefox
Description
JIT miscompilation in the JavaScript Engine: JIT component. This vulnerability was fixed in Firefox 149, Firefox ESR 115.34, Firefox ESR 140.9, Thunderbird 149, and Thunderbird 140.9.
CVSS v3.1
Score 8.8high
Affected software
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AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
CVE-2026-4698 involves a Just-In-Time (JIT) miscompilation issue within the JavaScript Engine's JIT component in Mozilla Firefox. This vulnerability was identified and reported by security researchers and fixed in Firefox 149, Firefox ESR 115.34, and Firefox ESR 140.9. The CVSS v3.1 score is 8.8, indicating a high severity with network attack vector, low attack complexity, no privileges required, user interaction required, and impacts to confidentiality, integrity, and availability. The vendor advisories confirm the fix and provide detailed references to the underlying bugs. No known exploits in the wild have been reported at this time.
Potential Impact
Successful exploitation of this vulnerability could allow an attacker to execute arbitrary code or cause significant disruption to the affected Firefox browser, impacting confidentiality, integrity, and availability. The high CVSS score reflects the critical nature of the vulnerability in the JavaScript engine's JIT compilation process.
Mitigation Recommendations
Mozilla has released official fixes for this vulnerability in Firefox 149, Firefox ESR 115.34, and Firefox ESR 140.9. Users and administrators should update affected Firefox installations to these versions or later to mitigate the risk. No additional mitigation steps are required beyond applying the official patches.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- mozilla
- Date Reserved
- 2026-03-23T23:21:58.886Z
- Cvss Version
- null
- State
- PUBLISHED
- Vendor Advisory Urls
- [{"url":"https://www.mozilla.org/security/advisories/mfsa2026-20/","vendor":"Mozilla"},{"url":"https://www.mozilla.org/security/advisories/mfsa2026-21/","vendor":"Mozilla"},{"url":"https://www.mozilla.org/security/advisories/mfsa2026-22/","vendor":"Mozilla"},{"url":"https://www.mozilla.org/security/advisories/mfsa2026-23/","vendor":"Mozilla"},{"url":"https://www.mozilla.org/security/advisories/mfsa2026-24/","vendor":"Mozilla"}]
Threat ID: 69c28784f4197a8e3b3205b7
Added to database: 03/24/2026, 12:45:56 UTC
Last enriched: 07/15/2026, 08:13:26 UTC
Last updated: 07/31/2026, 19:22:59 UTC
Views: 147
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