cbcvebase.
CVE-2026-0891
published 2026-01-13

CVE-2026-0891: Memory safety bugs present in Firefox ESR 140.6, Thunderbird ESR 140.6, Firefox 146 and Thunderbird 146. Some of these bugs showed evidence of memory…

high8.1CVSS 3.1
AVNACHPRNUINSUCHIHAH
Memory safety bugs present in Firefox ESR 140.6, Thunderbird ESR 140.6, Firefox 146 and Thunderbird 146. 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 147, Firefox ESR 140.7, Thunderbird 147, and Thunderbird 140.7.

Affected

12 ranges
VendorProductVersion rangeFixed in
debianfirefox< firefox 147.0-1 (sid)firefox 147.0-1 (sid)
debianfirefox-esr< firefox 147.0-1 (sid)firefox 147.0-1 (sid)
debianthunderbird< firefox 147.0-1 (sid)firefox 147.0-1 (sid)
mozillafirefox< 140.7.0140.7.0
mozillafirefox< 147.0147.0
mozillafirefox
mozillathunderbird< 140.7.0140.7.0
mozillathunderbird< 147.0147.0
mozillathunderbird>= 0 < 1:140.7.0esr-1~deb11u11:140.7.0esr-1~deb11u1
mozillathunderbird>= 0 < 1:140.7.0esr-1~deb12u11:140.7.0esr-1~deb12u1
mozillathunderbird>= 0 < 1:140.7.0esr-1~deb13u11:140.7.0esr-1~deb13u1
mozillathunderbird>= 0 < 1:140.7.0esr-11:140.7.0esr-1

CVSS provenance

nvdv3.18.1HIGHCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
osv8.1HIGH