Name: CVE-2026-57963: Improper Neutralization of Input During Web Page Generation
Creator: Rapid7
Published: 2026-07-01T00:00:00.000Z
License: https://www.rapid7.com/legal/website-terms-of-use/
Keywords: CVE, CVE-2026-57963, CWE-79, CVSS 6.5, EPSS 0.00142

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.

CVSS Details

CVSS 3.1 Base Score: 6.5
CVSS 3.1 Vector: (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N)

Covered by Rapid7

Product	Vendor Advisory	Solution File	Added	Published
Amazon Linux Ami 2	—	Upgrade thunderbird	Oct 19, 2026	Oct 19, 2026
Debian	—	Upgrade thunderbird	Aug 9, 2026	Aug 9, 2026
Mozilla Thunderbird	—	Upgrade to the latest version of Mozilla ThunderbirdUpgrade to Mozilla Thunderbird version 140.12.1	Jul 1, 2026	Jun 30, 2026

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CVSS Details

Covered by Rapid7

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