CVE-2026-6758: Vulnerability in Mozilla Firefox
Use-after-free in the JavaScript: WebAssembly component. This vulnerability was fixed in Firefox 150 and Thunderbird 150.
AI Analysis
Technical Summary
CVE-2026-6758 is a use-after-free vulnerability affecting the JavaScript: WebAssembly component in Mozilla Firefox. Use-after-free vulnerabilities occur when a program continues to use a pointer after the memory it points to has been freed, potentially leading to memory corruption or other unintended behavior. This specific vulnerability was fixed in Firefox 150 as part of a broader set of memory safety bug fixes. The vendor advisory classifies the impact as moderate and no active exploitation has been reported.
Potential Impact
The vulnerability could allow an attacker to cause memory corruption via use-after-free in the WebAssembly component, which might be leveraged to affect the stability or security of the browser. The vendor advisory rates the impact as moderate. There are no reports of known exploitation in the wild.
Mitigation Recommendations
An official fix is available and was released in Firefox 150. Users and administrators should update to Firefox 150 or later to remediate this vulnerability. No additional mitigation steps are indicated by the vendor advisory.
CVE-2026-6758: Vulnerability in Mozilla Firefox
Description
Use-after-free in the JavaScript: WebAssembly component. This vulnerability was fixed in Firefox 150 and Thunderbird 150.
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
CVE-2026-6758 is a use-after-free vulnerability affecting the JavaScript: WebAssembly component in Mozilla Firefox. Use-after-free vulnerabilities occur when a program continues to use a pointer after the memory it points to has been freed, potentially leading to memory corruption or other unintended behavior. This specific vulnerability was fixed in Firefox 150 as part of a broader set of memory safety bug fixes. The vendor advisory classifies the impact as moderate and no active exploitation has been reported.
Potential Impact
The vulnerability could allow an attacker to cause memory corruption via use-after-free in the WebAssembly component, which might be leveraged to affect the stability or security of the browser. The vendor advisory rates the impact as moderate. There are no reports of known exploitation in the wild.
Mitigation Recommendations
An official fix is available and was released in Firefox 150. Users and administrators should update to Firefox 150 or later to remediate this vulnerability. No additional mitigation steps are indicated by the vendor advisory.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- mozilla
- Date Reserved
- 2026-04-21T12:40:53.328Z
- Cvss Version
- null
- State
- PUBLISHED
- Remediation Level
- null
- Vendor Advisory Urls
- [{"url":"https://www.mozilla.org/security/advisories/mfsa2026-30/","vendor":"Mozilla"}]
Threat ID: 69e7789c19fe3cd2cdd163d6
Added to database: 4/21/2026, 1:16:12 PM
Last enriched: 4/21/2026, 1:46:24 PM
Last updated: 4/22/2026, 5:41:17 AM
Views: 10
Community Reviews
0 reviewsCrowdsource mitigation strategies, share intel context, and vote on the most helpful responses. Sign in to add your voice and help keep defenders ahead.
Want to contribute mitigation steps or threat intel context? Sign in or create an account to join the community discussion.
Actions
Updates to AI analysis require Pro Console access. Upgrade inside Console → Billing.
Need more coverage?
Upgrade to Pro Console for AI refresh and higher limits.
For incident response and remediation, OffSeq services can help resolve threats faster.
Latest Threats
Check if your credentials are on the dark web
Instant breach scanning across billions of leaked records. Free tier available.