by Kastro
Paper/Archive/CVE-2026-5735

CVE-2026-5735

Mozilla Firefox — Memory safety bugs fixed in Firefox 149.0.2 and Thunderbird 149.0.2

EPSS 0.3%CVSS 9.8
critical.is priorityof 100
33
CVSS 9.8 (NVD)9.8 / 10 × 3029.4Not in CISA KEV+300.0EPSS percentile 17.3.173 × 203.5No public exploit+100.0SSVC exploitation: none+100.0
Description · from the CVE record

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.

Affected

ProductAffectedFixed inSource
Firefoxsee advisory149.0.2CNA
Thunderbirdsee advisory149.0.2CNA
Red Hat Enterprise Linux 10see advisory–redhat-SADP
Red Hat Enterprise Linux 10see advisory–redhat-SADP
Red Hat Enterprise Linux 6see advisory–redhat-SADP
Red Hat Enterprise Linux 7see advisory–redhat-SADP
Red Hat Enterprise Linux 8see advisory–redhat-SADP
Red Hat Enterprise Linux 9see advisory–redhat-SADP

Scores by source

NVD9.8CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
CISA ADP8.1CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
redhat-SADP (CNA)7.5CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H
CISA ADPSSVCExploitation: none · Automatable: no · Technical impact: total

References

refbugzilla.mozilla.org/buglist.cgi?bug_id=2025475%2C2025477refmozilla.org/security/advisories/mfsa2026-25refmozilla.org/security/advisories/mfsa2026-28refaccess.redhat.com/security/cve/CVE-2026-5735refbugzilla.redhat.com/show_bug.cgi?id=2455904refsecurity.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-5735.json