CVE-2026-57963
An attacker can exploit multiple vulnerabilities in Mozilla Thunderbird to conduct a denial of service attack and to present false information.
CSIRTS triage
- What
- Multiple vulnerabilities can lead to denial of service attacks and present false information.
- Who is affected
- Users of Mozilla Thunderbird.
- Urgency
- Remediation is medium urgency due to the potential impact of the vulnerabilities.
- Action
- Update to the latest version of Thunderbird.
AI-assisted analysis generated from the source advisory — verify against the original.
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Exploitation outlook
- Low exploitation risk0.19% 30-day exploitation probability — currently an unlikely target, but scores change as exploit code circulates. Riskier than 9% of all EPSS-scored CVEs.
Advisory coverage (5)
- medium[UPDATE] [medium] Mozilla Thunderbird: Multiple vulnerabilitiescert-bund · 2026-08-18
- unknownDSA-6418-1 thunderbird - security updatedebian · 2026-08-07
- unknownMozilla Products Multiple Vulnerabilitieshkcert · 2026-07-02
- unknownMultiple vulnerabilities in Mozilla Thunderbird (July 2, 2026)cert-fr-avis · 2026-07-02
- mediumCVE-2026-57963: An attacker who can send HTML chat messages (via Matrix or XMPP) can inject arbitrary styled c…nvd · 2026-07-01
External references
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