Memory safety bugs fixed in Firefox 149.0.2 and Thunderbird 149.0.2
21Vexday Risk Score
No sign of exploitation. No public exploitation artifact known so far.
ssvc Trackcvss 8.1epss 0.3%
exploitation probability
0.3%top 83% of all CVEs
observed exploitation
nono source reports it
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.
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
References
https://access.redhat.com/security/cve/CVE-2026-5735https://bugzilla.mozilla.org/buglist.cgi?bug_id=2025475%2C2025477https://bugzilla.redhat.com/show_bug.cgi?id=2455904https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-5735.jsonhttps://www.mozilla.org/security/advisories/mfsa2026-25/https://www.mozilla.org/security/advisories/mfsa2026-28/