CVE-2026-0891

Public on 2026-01-13

Modified on 2026-01-15

Description

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 affects Firefox < 147 and Firefox ESR < 140.7.

Severity

Important

See what this means

CVSS v3 Base Score

8.1

See breakdown

Affected Packages

Platform	Package	Status
Amazon Linux 2 - Firefox Extra	firefox	Pending Fix
Amazon Linux 2023	firefox	Pending Fix
Amazon Linux 2 - Core	thunderbird	Pending Fix

CVSS Scores

	Score Type	Score	Vector
Amazon Linux	CVSSv3	8.1	CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H

References

FAQs regarding Amazon Linux ALAS/CVE Severity Red Hat: CVE-2026-0891 Mitre: CVE-2026-0891