CVE-2026-118179

critical

Description

Clicking a news: or snews: link that referenced a message-ID made Thunderbird connect, without asking, to the host and port given in the link, even if it was not a configured news server. Line breaks in the message-ID were sent to the server unmodified, so a crafted link could send arbitrary commands to services reachable from the user's network. In addition, snews: links to such servers connected without TLS. This vulnerability was fixed in Thunderbird 159 and Thunderbird 153.6.

References

https://www.mozilla.org/security/advisories/mfsa2026-122/

https://www.mozilla.org/security/advisories/mfsa2026-121/

https://euvd.enisa.europa.eu/vulnerability/EUVD-2026-111356

https://bugzilla.mozilla.org/show_bug.cgi?id=2077789

Details

Source: Mitre, NVD

Published: 2026-10-27

Updated: 2026-10-28

Risk Information

CVSS v2

Base Score: 8.8

Vector: CVSS2#AV:N/AC:M/Au:N/C:C/I:C/A:N

Severity: High

CVSS v3

Base Score: 9.8

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

Severity: Critical

EPSS

EPSS: 0.00179