UBUNTU-CVE-2026-117889: Medium severity ubuntu/mozjs52 vulnerability

Published Oct 27, 2026

Updated

Incorrect boundary conditions in the JavaScript Engine component. This vulnerability was fixed in Firefox 159, Firefox ESR 115.44, Firefox ESR 153.6, Thunderbird 159, and Thunderbird 153.6.

Affected Software

10 affected components

ubuntu/mozjs52*

ubuntu/mozjs38*

ubuntu/mozjs68*

ubuntu/mozjs52*

ubuntu/mozjs102*

ubuntu/mozjs78*

ubuntu/mozjs91*

ubuntu/thunderbird*

ubuntu/mozjs102*

ubuntu/mozjs115*

Remediation

Recommended actions to resolve this vulnerability, in priority order.

Upgrade
Upgrade Firefox to a version that resolves this vulnerability.
Fixed in 159
Upgrade
Upgrade Firefox ESR to a version that resolves this vulnerability.
Fixed in 115.44
Upgrade
Upgrade Firefox ESR to a version that resolves this vulnerability.
Fixed in 153.6
Upgrade
Upgrade Thunderbird to a version that resolves this vulnerability.
Fixed in 159
Upgrade
Upgrade Thunderbird to a version that resolves this vulnerability.
Fixed in 153.6

Event History

Oct 27, 2026

CVE Published

via OSV·02:16 PM

Data Sourced

via OSV·02:16 PM

DescriptionSeverityAffected Software

Frequently Asked Questions

Which Ubuntu packages should be reviewed for exposure?

The listed Ubuntu packages are mozjs38, mozjs52, mozjs68, mozjs78, mozjs91, mozjs102, mozjs115, and thunderbird. Review installed versions and Ubuntu security update status for each package in use.

Which upstream releases include the fix?

The issue was fixed in Firefox 159, Firefox ESR 115.44, Firefox ESR 153.6, Thunderbird 159, and Thunderbird 153.6.