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, with active exploitation. 3 of its known vulnerabilities are being actively exploited in the wild (CISA KEV), including CVE-2024-9680. Upgrade immediately and review your exposure to the actively-exploited CVEs below.
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.
1 of its known vulnerability is linked to ransomware campaigns (CISA KEV).
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-2024-9680 CRITICAL exploited ransomware Use-after-free EPSS 23% → fixed in 128.3.1 CVE-2022-26485 HIGH exploited Use-after-free EPSS 14% → fixed in 91.6.2 CVE-2022-26486 CRITICAL exploited Use-after-free EPSS 2% → fixed in 91.6.2 CVE-2025-4918 CRITICAL Out-of-bounds read EPSS 9% → fixed in 138.0.2 CVE-2025-0247 CRITICAL Out-of-bounds write EPSS 9% → fixed in 134.0 CVE-2025-1009 CRITICAL Use-after-free EPSS 1% → fixed in 135.0 CVE-2023-29531 CRITICAL Out-of-bounds write EPSS 1% → fixed in 102.10 CVE-2023-29542 CRITICAL EPSS 1% → fixed in 102.10 CVE-2023-34416 CRITICAL Out-of-bounds write EPSS 1% → fixed in 102.12 CVE-2024-3863 CRITICAL Unrestricted file upload EPSS 1% → fixed in 115.10 CVE-2026-74987 CRITICAL Memory corruption EPSS 1% → fixed in 153.1.0 CVE-2026-74990 CRITICAL Memory corruption EPSS 1% → fixed in 153.1.0See all 637 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, with active exploitation. 3 of its known vulnerabilities are being actively exploited in the wild (CISA KEV), including CVE-2024-9680. Upgrade immediately and review your exposure to the actively-exploited CVEs below.
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. Some issues are under active exploitation, so treat this as urgent.
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 ↗