CVE-2026-57963

UNKNOWN 0.0

Chat UI manipulation by injection

CVSS Score

0.0

EPSS Score

0.0%

EPSS Percentile

0th

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.

Vendor	mozilla
Product	thunderbird
Ecosystems	Browser JavaScript
Industries	Technology
Published	Jul 1, 2026

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Affected Versions

Mozilla / Thunderbird

All versions affected

References

NVD ↗ CVE.org ↗ EPSS Data ↗

bugzilla.mozilla.org: https://bugzilla.mozilla.org/show_bug.cgi?id=2042910 mozilla.org: https://www.mozilla.org/security/advisories/mfsa2026-62/ mozilla.org: https://www.mozilla.org/security/advisories/mfsa2026-63/

Credits

Michael Bommarito