CVE-2026-57963
Last modified
CVE-2026-57963 is a medium-severity vulnerability rated 6.5/10 on the CVSS scale. 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.. EPSS estimates a 0.19% chance of exploitation in the next 30 days.
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.
Metrics
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N
Weakness Enumeration
Affected Software
| Vendor | Product | Versions |
|---|---|---|
| Mozilla | Thunderbird | < 140.12.1 |
| Mozilla | Thunderbird | < 152.0.1 |
References
- https://bugzilla.mozilla.org/show_bug.cgi?id=2042910Permissions Required
- https://www.mozilla.org/security/advisories/mfsa2026-63/Vendor Advisory
- https://www.mozilla.org/security/advisories/mfsa2026-64/Vendor Advisory
Timeline
- Published
- Last Modified
- Status
- Analyzed
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How Strix Helps
- How Strix found a critical auth bypass in etcdStrix autonomously discovered a critical authentication bypass in etcd, later designated CVE-2026-33413.
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