Critical severity · published Jul 21, 2026
CVE-2026-16411
Memory safety bugs fixed in Thunderbird 153
9.8
CVSS
0.6%
EPSS
No
On KEV
Description
Memory safety bugs present in Thunderbird 152. 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 153 and Thunderbird 153.
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)0.6% · higher than 47% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
FI
Firefox · Mozilla
before 153.0.0 · source: NVD
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-16411
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-16411
Broken Link
https://bugzilla.mozilla.org/buglist.cgi?bug_id=1420800%2C1598946%2C1767921%2C2013993%2C2025417%2C2027325%2C2027364%2C2029433%2C2029807%2C2029901%2C2029922%2C2030102%2C2030563%2C2032110%2C2037801%2C2042756%2C2044625%2C2045609%2C2047920%2C2048491%2C2048492%2C2048800%2C2050534%2C2050662%2C2050871
Broken Link
https://bugzilla.mozilla.org/buglist.cgi?bug_id=2006467%2C2027346%2C2027349%2C2027353%2C2027362%2C2027371%2C2027373%2C2028954%2C2029694%2C2036906%2C2038964%2C2039460%2C2040522%2C2040834%2C2043275%2C2045394%2C2045606%2C2052060
Broken Link
https://bugzilla.mozilla.org/buglist.cgi?bug_id=2048936%2C2049804
Vendor Advisory
https://www.mozilla.org/security/advisories/mfsa2026-68/
www.mozilla.org
https://www.mozilla.org/security/advisories/mfsa2026-71/
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