Critical severity · published Jul 21, 2026
CVE-2026-16357
Incorrect boundary conditions in the Graphics component
9.8
CVSS
0.6%
EPSS
No
On KEV
Description
Incorrect boundary conditions in the Graphics component. This vulnerability was fixed in Firefox 153, Firefox ESR 115.38, Firefox ESR 140.13, Thunderbird 153, and Thunderbird 140.13.
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 48% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
FI
Firefox · Mozilla
before 115.38.0; before 153.0.0; 128.1.0 before 140.13.0 · source: NVD
TH
Thunderbird · Mozilla
before 140.13.0; 141.0 before 153.0 · source: NVD
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-16357
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-16357
Permissions Required
https://bugzilla.mozilla.org/show_bug.cgi?id=2053326
Vendor Advisory
https://www.mozilla.org/security/advisories/mfsa2026-68/
Vendor Advisory
https://www.mozilla.org/security/advisories/mfsa2026-69/
Vendor Advisory
https://www.mozilla.org/security/advisories/mfsa2026-70/
Vendor Advisory
https://www.mozilla.org/security/advisories/mfsa2026-71/
Vendor Advisory
https://www.mozilla.org/security/advisories/mfsa2026-72/
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