Critical severity · published Feb 24, 2026
CVE-2026-2807
Memory safety bugs fixed in Firefox 148 and Thunderbird 148
9.8
CVSS
0.3%
EPSS
No
On KEV
Description
Memory safety bugs present in Firefox 147 and Thunderbird 147. 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 148 and Thunderbird 148.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Confidentiality
High
Integrity
High
Availability
High
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.3% · higher than 22% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
FI
Firefox · Mozilla
before 148.0 · source: NVD
TH
Thunderbird · Mozilla
before 148.0 · source: NVD
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-2807
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-2807
Broken Link
https://bugzilla.mozilla.org/buglist.cgi?bug_id=1756056%2C1999402%2C2004872%2C2006037%2C2012855
Vendor Advisory
https://www.mozilla.org/security/advisories/mfsa2026-13/
Vendor Advisory
https://www.mozilla.org/security/advisories/mfsa2026-16/
access.redhat.com
https://access.redhat.com/security/cve/CVE-2026-2807
bugzilla.redhat.com
https://bugzilla.redhat.com/show_bug.cgi?id=2442296
security.access.redhat.com
https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-2807.json
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