Critical severity9.8NVD Advisory· Published Apr 7, 2026· Updated May 10, 2026

CVE-2026-5735

Description

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 products

Mozilla Corporation/Firefox
cpe:2.3:a:mozilla:firefox:*:*:*:*:-:*:*:*
Range: <149.0.2
Mozilla Corporation/Thunderbird
cpe:2.3:a:mozilla:thunderbird:*:*:*:*:-:*:*:*
Range: <149.0.2

Patches

No patches discovered yet.

Vulnerability mechanics

AI mechanics synthesis has not run for this CVE yet.

References

www.mozilla.org/security/advisories/mfsa2026-25/nvdVendor Advisory
bugzilla.mozilla.org/buglist.cginvdBroken LinkIssue Tracking
www.mozilla.org/security/advisories/mfsa2026-28/nvd

News mentions

No linked articles in our index yet.

cvss	0.637
epss	0.000
exploit	0.000
kev	0.000
patch	0.000
ransomware	0.000