CVE-2026-74936: Vulnerability in Mozilla Firefox
CVE-2026-74936 is a critical use-after-free vulnerability in the JavaScript WebAssembly component of Mozilla Firefox. This flaw allows for potential memory corruption and was fixed in Firefox 154 and Firefox ESR versions 140.14 and 153.1. The vulnerability has a CVSS score of 9.8, indicating high severity with network attack vector, no required privileges or user interaction, and impacts confidentiality, integrity, and availability. No known exploits in the wild have been reported. The vendor has released official patches to address this issue.
AI Analysis
Technical Summary
CVE-2026-74936 is a use-after-free vulnerability found in the JavaScript WebAssembly component of Mozilla Firefox. This vulnerability could lead to memory corruption and potentially allow an attacker to execute arbitrary code or cause a denial of service. It was reported by Amy Burnett of OpenAI and fixed in Firefox 154, Firefox ESR 140.14, and Firefox ESR 153.1. The CVSS v3.1 base score is 9.8, reflecting critical impact with network attack vector, low attack complexity, no privileges required, no user interaction, and high impact on confidentiality, integrity, and availability.
Potential Impact
The vulnerability allows remote attackers to exploit a use-after-free condition in the WebAssembly component, potentially leading to arbitrary code execution or denial of service. The critical CVSS score of 9.8 reflects the severity and ease of exploitation without user interaction or privileges. However, no active exploitation in the wild has been reported at this time.
Mitigation Recommendations
Mozilla has released official fixes for this vulnerability in Firefox 154, Firefox ESR 140.14, and Firefox ESR 153.1. Users and administrators should update to these versions or later to mitigate the risk. No additional mitigation actions are required beyond applying the official patches.
CVE-2026-74936: Vulnerability in Mozilla Firefox
Description
CVE-2026-74936 is a critical use-after-free vulnerability in the JavaScript WebAssembly component of Mozilla Firefox. This flaw allows for potential memory corruption and was fixed in Firefox 154 and Firefox ESR versions 140.14 and 153.1. The vulnerability has a CVSS score of 9.8, indicating high severity with network attack vector, no required privileges or user interaction, and impacts confidentiality, integrity, and availability. No known exploits in the wild have been reported. The vendor has released official patches to address this issue.
CVSS v3.1
Score 9.8critical
Affected software
Mozilla
Firefox
Mozilla
Thunderbird
pkg:github/mozilla/firefox-esrRun on your own infrastructure? Check whether these packages are installed with threat-finder — our free open-source scanner.
Weaknesses
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
CVE-2026-74936 is a use-after-free vulnerability found in the JavaScript WebAssembly component of Mozilla Firefox. This vulnerability could lead to memory corruption and potentially allow an attacker to execute arbitrary code or cause a denial of service. It was reported by Amy Burnett of OpenAI and fixed in Firefox 154, Firefox ESR 140.14, and Firefox ESR 153.1. The CVSS v3.1 base score is 9.8, reflecting critical impact with network attack vector, low attack complexity, no privileges required, no user interaction, and high impact on confidentiality, integrity, and availability.
Potential Impact
The vulnerability allows remote attackers to exploit a use-after-free condition in the WebAssembly component, potentially leading to arbitrary code execution or denial of service. The critical CVSS score of 9.8 reflects the severity and ease of exploitation without user interaction or privileges. However, no active exploitation in the wild has been reported at this time.
Mitigation Recommendations
Mozilla has released official fixes for this vulnerability in Firefox 154, Firefox ESR 140.14, and Firefox ESR 153.1. Users and administrators should update to these versions or later to mitigate the risk. No additional mitigation actions are required beyond applying the official patches.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- mozilla
- Date Reserved
- 2026-08-17T11:57:29.210Z
- State
- PUBLISHED
- Vendor Advisory Urls
- [{"url":"https://www.mozilla.org/security/advisories/mfsa2026-74/","vendor":"Mozilla"},{"url":"https://www.mozilla.org/security/advisories/mfsa2026-76/","vendor":"Mozilla"},{"url":"https://www.mozilla.org/security/advisories/mfsa2026-77/","vendor":"Mozilla"}]
Threat ID: 6a845502c6e8be033236739b
Added to database: 08/18/2026, 12:50:10 UTC
Last enriched: 09/11/2026, 22:03:59 UTC
Last updated: 10/02/2026, 04:48:18 UTC
Views: 48
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