[UPDATE] [high] Mozilla Thunderbird, Firefox ESR and Firefox: Multiple vulnerabilities
An attacker can exploit multiple vulnerabilities in Mozilla Thunderbird, Mozilla Firefox ESR, and Mozilla Firefox to escalate privileges, conduct a Denial of Service attack, disclose information, present false information, and bypass security measures.
CSIRTS triage
- What
- Multiple vulnerabilities can be exploited to escalate privileges, conduct a Denial of Service attack, disclose information, present false information, and bypass security measures.
- Who is affected
- Users of Mozilla Thunderbird, Firefox ESR, and Firefox.
- Urgency
- Remediation is urgent due to the high severity and multiple attack vectors.
- Action
- Update to the latest versions of Mozilla Thunderbird, Firefox ESR, and Firefox.
AI-assisted analysis generated from the source advisory — verify against the original.
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Details
Original advisory: https://wid.cert-bund.de/portal/wid/securityadvisory?name=WID-SEC-2026-1228
Exploitation outlook
EPSS (FIRST.org) estimates each CVE’s probability of exploitation in the next 30 days — here is the CSIRTS.com read on those numbers.
- Low exploitation riskCVE-2026-67480.40% 30-day exploitation probability — currently an unlikely target, but scores change as exploit code circulates. Riskier than 33% of all scored CVEs.
- Low exploitation riskCVE-2026-67500.48% 30-day exploitation probability — currently an unlikely target, but scores change as exploit code circulates. Riskier than 39% of all scored CVEs.
- Elevated exploitation riskCVE-2026-3362645.3% 30-day exploitation probability — well above the norm. Schedule remediation this cycle. Riskier than 99% of all scored CVEs.
- Low exploitation riskCVE-2026-27810.36% 30-day exploitation probability — currently an unlikely target, but scores change as exploit code circulates. Riskier than 29% of all scored CVEs.
- Low exploitation riskCVE-2026-67460.59% 30-day exploitation probability — currently an unlikely target, but scores change as exploit code circulates. Riskier than 45% of all scored CVEs.
- Low exploitation riskCVE-2026-67470.40% 30-day exploitation probability — currently an unlikely target, but scores change as exploit code circulates. Riskier than 33% of all scored CVEs.
- Low exploitation riskCVE-2026-67490.40% 30-day exploitation probability — currently an unlikely target, but scores change as exploit code circulates. Riskier than 33% of all scored CVEs.
- Low exploitation riskCVE-2026-67510.31% 30-day exploitation probability — currently an unlikely target, but scores change as exploit code circulates. Riskier than 23% of all scored CVEs.
- Low exploitation riskCVE-2026-67520.31% 30-day exploitation probability — currently an unlikely target, but scores change as exploit code circulates. Riskier than 23% of all scored CVEs.
- Low exploitation riskCVE-2026-67530.31% 30-day exploitation probability — currently an unlikely target, but scores change as exploit code circulates. Riskier than 23% of all scored CVEs.
Referenced CVEs
Recent advisories for Mozilla Thunderbird
A cluster of recent advisories against the same product widens the attack surface — attackers routinely chain freshly published CVEs on one product, so review these together.
- unknownMultiple vulnerabilities in Mozilla Thunderbird (July 23, 2026)cert-fr-avis · 2026-07-23
- high[UPDATE] [high] Mozilla Firefox, Firefox ESR and Thunderbird: Multiple vulnerabilitiescert-bund · 2026-07-22
- high[UPDATE] [high] Mozilla Firefox and Thunderbird: Multiple vulnerabilitiescert-bund · 2026-07-21
- medium[UPDATE] [medium] Mozilla Thunderbird: Multiple vulnerabilitiescert-bund · 2026-07-03
- unknownMultiple vulnerabilities in Mozilla Thunderbird (July 2, 2026)cert-fr-avis · 2026-07-02
- criticalexploitedCVE-2016-9079: Mozilla Firefox, Firefox ESR, and Thunderbird Use-After-Free Vulnerabilitycisa-kev · 2023-06-22
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