CVE-2026-2781

Publication date 24 February 2026

Last updated 27 February 2026


Ubuntu priority

Cvss 3 Severity Score

9.8 · Critical

Score breakdown

Description

Integer overflow in the Libraries component in NSS. This vulnerability affects Firefox < 148, Firefox ESR < 140.8, Thunderbird < 148, and Thunderbird < 140.8.

Read the notes from the security team

Status

Package Ubuntu Release Status
firefox 25.10 questing
Not affected
24.04 LTS noble
Not affected
22.04 LTS jammy
Not affected
thunderbird 25.10 questing
Not affected
24.04 LTS noble
Not affected
22.04 LTS jammy
Vulnerable
nss 25.10 questing
Needs evaluation
24.04 LTS noble
Needs evaluation
22.04 LTS jammy
Needs evaluation
20.04 LTS focal
Needs evaluation
18.04 LTS bionic
Needs evaluation
16.04 LTS xenial
Needs evaluation
14.04 LTS trusty
Needs evaluation

Notes


mdeslaur

mozjs* contain a copy of the SpiderMonkey JavaScript engine. It is not feasible to backport security fixes to the mozjs* packages, as such, marking them as ignored. starting with Ubuntu 22.04, the firefox package is just a script that installs the Firefox snap starting with Ubuntu 24.04, the thunderbird package is just a script that installs the Thunderbird snap

Patch details

For informational purposes only. We recommend not to cherry-pick updates. How can I get the fixes?

Package Patch details
nss

Severity score breakdown

Parameter Value
Base score 9.8 · Critical
Attack vector Network
Attack complexity Low
Privileges required None
User interaction None
Scope Unchanged
Confidentiality High
Integrity impact High
Availability impact High
Vector CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H