🔐 CVE Alert

CVE-2026-5735

HIGH 8.1

Memory safety bugs fixed in Firefox 149.0.2 and Thunderbird 149.0.2

CVSS Score
8.1
EPSS Score
0.0%
EPSS Percentile
0th

Memory safety bugs present in Firefox 149.0.1 and Thunderbird 149.0.1. 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 149.0.2 and Thunderbird 149.0.2.

Vendor mozilla
Product firefox
Ecosystems
Industries
Technology
Published Apr 7, 2026
Last Updated Apr 13, 2026
Stay Ahead of the Next One

Get instant alerts for mozilla firefox

Be the first to know when new high 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

NVD ↗ CVE.org ↗ EPSS Data ↗
bugzilla.mozilla.org: https://bugzilla.mozilla.org/buglist.cgi?bug_id=2025475%2C2025477 mozilla.org: https://www.mozilla.org/security/advisories/mfsa2026-25/ mozilla.org: https://www.mozilla.org/security/advisories/mfsa2026-28/

Credits

Brian Grinstead, Christian Holler and the Mozilla Fuzzing Team