An attacker who can send HTML chat messages (via Matrix or XMPP) can inject arbitrary styled content, phishing links, and CSS that manipulates the chat UI. This vulnerability was fixed in Thunderbird 152.0.1 and Thunderbird 140.12.1.
History

Wed, 01 Jul 2026 14:30:00 +0000

Type Values Removed Values Added
Weaknesses CWE-79
References
Metrics cvssV3_1

{'score': 6.5, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N'}

ssvc

{'options': {'Automatable': 'yes', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}


Wed, 01 Jul 2026 11:30:00 +0000

Type Values Removed Values Added
First Time appeared Mozilla
Mozilla thunderbird
Vendors & Products Mozilla
Mozilla thunderbird

Wed, 01 Jul 2026 11:15:00 +0000

Type Values Removed Values Added
Weaknesses CWE-79

Wed, 01 Jul 2026 03:30:00 +0000

Type Values Removed Values Added
Weaknesses CWE-79

Wed, 01 Jul 2026 01:30:00 +0000

Type Values Removed Values Added
Description An attacker who can send HTML chat messages (via Matrix or XMPP) can inject arbitrary styled content, phishing links, and CSS that manipulates the chat UI. This vulnerability was fixed in Thunderbird 152.0.1 and Thunderbird 140.12.1.
Title Chat UI manipulation by injection
References

cve-icon MITRE

Status: PUBLISHED

Assigner: mozilla

Published: 2026-07-01T00:58:33.922Z

Updated: 2026-07-01T14:09:10.035Z

Reserved: 2026-06-26T15:27:32.832Z

Link: CVE-2026-57963

cve-icon Vulnrichment

Updated: 2026-07-01T14:08:57.183Z

cve-icon NVD

No data.

cve-icon Redhat

No data.