Critical severity9.8NVD Advisory· Published Aug 18, 2026· Updated Aug 21, 2026
CVE-2026-74936
CVE-2026-74936
Description
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.
Affected products
11- osv-coords10 versionspkg:rpm/almalinux/firefox-x11pkg:rpm/almalinux/firefoxpkg:rpm/almalinux/thunderbirdpkg:rpm/opensuse/MozillaFirefox&distro=openSUSE%20Tumbleweedpkg:rpm/opensuse/firefox-esr&distro=openSUSE%20Tumbleweedpkg:rpm/opensuse/MozillaThunderbird&distro=openSUSE%20Tumbleweedpkg:rpm/opensuse/mozilla-nspr&distro=openSUSE%20Leap%2016.0pkg:rpm/opensuse/mozilla-nss&distro=openSUSE%20Leap%2016.0pkg:rpm/opensuse/rust-cbindgen&distro=openSUSE%20Leap%2016.0pkg:rpm/opensuse/MozillaFirefox&distro=openSUSE%20Leap%2016.0
< 140.14.0-1.el9_8.alma.1+ 9 more
- (no CPE)range: < 140.14.0-1.el9_8.alma.1
- (no CPE)range: < 140.14.0-1.el9_8.alma.1
- (no CPE)range: < 140.14.0-1.el10_2.alma.1
- (no CPE)range: < 154.0-1.1
- (no CPE)range: < 153.1.0-1.1
- (no CPE)range: < 140.14.0-1.1
- (no CPE)range: < 4.39-160000.1.1
- (no CPE)range: < 3.125-160000.1.1
- (no CPE)range: < 0.29.4+git0-160000.1.1
- (no CPE)range: < 140.14.0-160000.1.1
Patches
Vulnerability mechanics
References
7- www.mozilla.org/security/advisories/mfsa2026-74/nvdVendor Advisory
- www.mozilla.org/security/advisories/mfsa2026-76/nvdVendor Advisory
- www.mozilla.org/security/advisories/mfsa2026-77/nvdVendor Advisory
- www.mozilla.org/security/advisories/mfsa2026-78/nvdVendor Advisory
- www.mozilla.org/security/advisories/mfsa2026-79/nvdVendor Advisory
- www.mozilla.org/security/advisories/mfsa2026-80/nvdVendor Advisory
- bugzilla.mozilla.org/show_bug.cginvdPermissions Required
News mentions
1- ⚡ Weekly Recap: AI-Powered PLC Attacks, GitLab Attacks, Stripe Key Leaks and MoreThe Hacker News · Aug 24, 2026