CVE-2026-6784

HIGH 7.5

Memory safety bugs fixed in Firefox 150 and Thunderbird 150

CVSS Score

7.5

EPSS Score

0.0%

EPSS Percentile

0th

Memory safety bugs present in Firefox 149 and Thunderbird 149. Some of these bugs showed evidence of memory corruption and we presume that with enough effort some of these could have been exploited to run arbitrary code. This vulnerability was fixed in Firefox 150.

Vendor	mozilla
Product	firefox
Ecosystems	Browser JavaScript
Industries	Technology
Published	Apr 21, 2026
Last Updated	Apr 21, 2026

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Affected Versions

Mozilla / Firefox

All versions affected

References

NVD ↗ CVE.org ↗ EPSS Data ↗

bugzilla.mozilla.org: https://bugzilla.mozilla.org/buglist.cgi?bug_id=1536243%2C1745382%2C1851073%2C1893400%2C1963301%2C2001319%2C2002899%2C2012436%2C2014435%2C2016901%2C2019916%2C2020486%2C2020612%2C2020817%2C2021788%2C2022051%2C2022367%2C2022431%2C2023302%2C2023670%2C2024225%2C2024238%2C2024240%2C2024265%2C2024367%2C2024369%2C2024424%2C2024760%2C2025281%2C2025361%2C2025387%2C2025466%2C2025954%2C2025958%2C2026278%2C2026292%2C2026297%2C2026378%2C2027148%2C2027287%2C2027341%2C2027384%2C2027427%2C2027694%2C2027993%2C2028009%2C2028270%2C2028416%2C2028524%2C2029295%2C2029301%2C2029461%2C2029699%2C2029800%2C2029801 mozilla.org: https://www.mozilla.org/security/advisories/mfsa2026-30/

Credits

Ben Visness, Brian Grinstead, Christian Holler, Dimi Lee, Jens Stutte, Jim Mathies, John Schanck, Jon Coppeard, Karl Tomlinson, Maurice Dauer, Nika Layzell, Randell Jesup, Tom Schuster and the Mozilla Fuzzing Team