CVE-2026-8956 Security Details

CVE ID

CVE-2026-8956

CWE

CWE-190

CVE Description

Integer overflow in the Networking: JAR component. This vulnerability was fixed in Firefox 151, Firefox ESR 140.11, Thunderbird 151, and Thunderbird 140.11.

Published

May 21, 2026

CVSS Score & Severity

9.8Critical

CVSS Vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

EPSS Score

0.064%

Malware

malware

KEV Status

Not in KEV Catalog: No known exploits

Affected Ecosystems

affected

Source

National Vulnerability Database

References

Bugzilla #2032427PROJECT

mozilla.orgPROJECT

mozilla.orgPROJECT