Mozilla Thunderbird ↗
Summary iPlain-English security verdict for Mozilla Thunderbird, generated from its current health score, actively-exploited vulnerabilities, and latest supported version.
Mozilla Thunderbird currently scores 5/100 — critical. No tracked vulnerabilities are currently known to be exploited in the wild. Upgrade promptly to address the open critical vulnerabilities.
Disclosure trend iNew CVEs published for Mozilla Thunderbird each year (NVD). A higher bar means more disclosures that year — more scrutiny, not necessarily less safe.
Patch priority — what to act on iThe issues to fix first — actively exploited (CISA KEV) first, then by exploitation probability (EPSS), then severity. Each row's "→ fixed in" is the earliest version that patches it; "see advisory" means no fixed version is published.
Most urgent first — actively exploited, then likeliest to be exploited.
CVE-2026-4689 CRITICAL Integer overflow EPSS 1% → fixed in 149.0 CVE-2026-2796 CRITICAL CWE-843 EPSS 1% → fixed in 148.0 CVE-2026-2773 CRITICAL Memory corruption EPSS 1% → fixed in 148.0 CVE-2026-2775 CRITICAL CWE-288 EPSS 1% → fixed in 148.0 CVE-2026-2762 CRITICAL Integer overflow EPSS 1% → fixed in 148.0 CVE-2026-2774 CRITICAL Integer overflow EPSS 1% → fixed in 148.0 CVE-2026-0879 CRITICAL Memory corruption EPSS 1% → fixed in 147.0 CVE-2026-2757 CRITICAL CWE-1384 EPSS 0% → fixed in 148.0 CVE-2026-4692 CRITICAL CWE-653 EPSS 0% → fixed in 149.0 CVE-2026-2771 CRITICAL Out-of-bounds read EPSS 0% → fixed in 148.0 CVE-2026-2776 CRITICAL Memory corruption EPSS 0% → fixed in 148.0 CVE-2026-2778 CRITICAL Memory corruption EPSS 0% → fixed in 148.0See all 167 known Mozilla Thunderbird CVEs & security history →
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Frequently asked
Is Mozilla Thunderbird safe and patched?
Mozilla Thunderbird currently scores 5/100 — critical. No tracked vulnerabilities are currently known to be exploited in the wild. Upgrade promptly to address the open critical vulnerabilities.
What should I do about Mozilla Thunderbird now?
Review the patch-priority list, apply the available fixes (or move to the latest release), and confirm against Mozilla's official advisory.
lifecycle unknown — needs latest supported version
Informational only, from public data (NVD · CISA KEV · EPSS · endoflife.date), and can lag or miss vendor-specific fixes. Always confirm against Mozilla's official advisory before you patch or upgrade — Mozilla Thunderbird official site ↗