CVE-2026-57963 json
Chat UI manipulation by injection
published 2026-07-01 4 mo ago modified 2026-10-25 15 d ago also EUVD-2026-40862
- cvss
- 6.5
- version 3.1, CNA
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 0.3%
- EPSS 0.3% chance of exploitation in 30 days, percentile 23%
- public exploits
- 0
- none known
Summary
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.
Patch / fix
- mozilla thunderbird 140.12.1, 152.0.1
- thunderbird Debian 12 1:140.13.0esr-2~deb12u1
- thunderbird Debian 13 1:140.13.0esr-2~deb13u1
- thunderbird Debian 14 1:140.13.0esr-1
debian advisories DEBIAN-CVE-2026-57963
- MozillaThunderbird openSUSE Tumbleweed 140.12.1-1.1
opensuse advisories openSUSE-SU-2026:11164-1
Vendor advisories
What the vendors themselves say about their products: affected, fixed or not affected, and what to do.
red hat product security vex CVE-2026-57963 updated cvss 7.5
thunderbird: Chat UI manipulation by injection
-
Red Hat Enterprise Linux 6 thunderbird Red Hat Enterprise Linux 7 thunderbird Red Hat Enterprise Linux 8 thunderbird Red Hat Enterprise Linux 9 thunderbird Red Hat Enterprise Linux 10 thunderbird, rhel10/thunderbird-flatpaknot affected: vulnerable code not present
Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf
CISA SSVC
- Exploitation
- none
- Automatable
- yes
- Technical impact
- partial
- Assessed
- 4 mo ago
Exploit prediction
0.31% chance of exploitation in the next 30 days, higher than 23% of all scored CVEs (FIRST EPSS, 2026-11-08).
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| CISA ADP | 3.1 | 6.5 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N |
| CNA | 3.1 | 6.5 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N |
Affected products
- Mozilla Thunderbird
Classification
- Weakness
-
- CWE-79 Improper Neutralization of Input During Web Page Generation
References
-
mozilla.org
/security/advisories/mfsa2026-63/
vendor-advisory
-
mozilla.org
/security/advisories/mfsa2026-64/
vendor-advisory
-
bugzilla.mozilla.org
/show_bug.cgi?id=2042910
permissions-required
Sources
- CVE List CVE-2026-57963
- NVD CVE-2026-57963
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