CVE-2026-74936
Use-after-free in the JavaScript: WebAssembly component
CVSS Score
9.8
EPSS Score
0.4%
EPSS Percentile
34th
Use-after-free in the JavaScript: WebAssembly component. This vulnerability was fixed in Firefox 154, Firefox ESR 140.14, Firefox ESR 153.1, Thunderbird 154, Thunderbird 140.14, and Thunderbird 153.1.
| Vendor | mozilla |
| Product | firefox |
| Ecosystems | |
| Industries | Technology |
| Published | Aug 18, 2026 |
| Last Updated | Aug 21, 2026 |
Stay Ahead of the Next One
Get instant alerts for mozilla firefox
Be the first to know when new critical vulnerabilities affecting mozilla firefox are published — delivered to Slack, Telegram or Discord.
Get Free Alerts →
Free · No credit card · 60 sec setup
Affected Versions
Mozilla / Firefox
All versions affected Mozilla / Thunderbird
All versions affected References
bugzilla.mozilla.org: https://bugzilla.mozilla.org/show_bug.cgi?id=2052688 mozilla.org: https://www.mozilla.org/security/advisories/mfsa2026-74/ mozilla.org: https://www.mozilla.org/security/advisories/mfsa2026-76/ mozilla.org: https://www.mozilla.org/security/advisories/mfsa2026-77/ mozilla.org: https://www.mozilla.org/security/advisories/mfsa2026-78/ mozilla.org: https://www.mozilla.org/security/advisories/mfsa2026-79/ mozilla.org: https://www.mozilla.org/security/advisories/mfsa2026-80/
Credits
Amy Burnett of OpenAI