[UPDATE] [medium] Mozilla Thunderbird: Multiple vulnerabilities

mediumCVE-2026-57962 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

vendor: Mozilla product: Thunderbird Denial of serviceOther

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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Details

Source: CERT-Bund (BSI) Security Advisories (DE · national-cert · site)
Severity: medium
Published: 2026-07-03
Exploitation: Not in CISA KEV at last sync
Language: Machine-translated to English — verify against the original

Original advisory: https://wid.cert-bund.de/portal/wid/securityadvisory?name=WID-SEC-2026-2178

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-2026-579620.20% 30-day exploitation probability — currently an unlikely target, but scores change as exploit code circulates. Riskier than 10% of all scored CVEs.
Low exploitation riskCVE-2026-579630.18% 30-day exploitation probability — currently an unlikely target, but scores change as exploit code circulates. Riskier than 8% of all scored CVEs.

Referenced CVEs

CVE	CSIRTS overview	External
CVE-2026-57962	coverage & exploitation status	NVD · CVE.org
CVE-2026-57963	coverage & exploitation status	NVD · CVE.org

Same CVEs, other sources

How other CERTs, PSIRTs and databases cover the vulnerabilities in this advisory.

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.

high[UPDATE] [high] Mozilla Firefox, Firefox ESR and Thunderbird: Multiple vulnerabilitiescert-bund · 2026-07-10
high[UPDATE] [high] Mozilla Firefox and Thunderbird: Multiple vulnerabilitiescert-bund · 2026-07-09
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
criticalexploitedCVE-2019-11707: Mozilla Firefox and Thunderbird Type Confusion Vulnerabilitycisa-kev · 2022-05-23
criticalexploitedCVE-2019-11708: Mozilla Firefox and Thunderbird Sandbox Escape Vulnerabilitycisa-kev · 2022-05-23