Is Svelte 4.2.20 patched?
Current stable (5.56.3): 92/100
4.2.20 has 1 open critical-or-high vulnerability. Run 104.8.0 or later to clear it. See what 104.8.0 fixes →
Summary iPlain-English security status for Svelte 4.2.20, built from its CVEs, active-exploitation data, end-of-life date and latest release.
Svelte 4.2.20 is part of the 4.2 release line. 7 known vulnerabilities affect it. The minimum safe version is 104.8.0 — upgrade to it or later to clear the open critical/high issues. The latest supported Svelte release is 5.56.3.
Known issues affecting 4.2.20
Exploited first, then by exploitation probability.
CVE-2021-29261 HIGH EPSS 1% → fixed in 104.8.0 CVE-2026-27125 MEDIUM EPSS 0% → fixed in 5.51.5 CVE-2026-27901 MEDIUM EPSS 0% → fixed in 5.53.5 CVE-2026-42573 MEDIUM EPSS 0% → fixed in 5.55.7 CVE-2026-27121 MEDIUM EPSS 0% → fixed in 5.51.5 CVE-2026-27122 MEDIUM EPSS 0% → fixed in 5.51.5 CVE-2026-42599 MEDIUM EPSS 0% → fixed in 5.55.7Other Svelte versions
Check another release line of Svelte.
Frequently asked
Is Svelte 4.2.20 patched?
Svelte 4.2.20 has 1 open critical-or-high vulnerability. The minimum safe version is 104.8.0 — upgrade to 104.8.0 or later to clear it.
What version should I upgrade Svelte 4.2.20 to?
Upgrade Svelte 4.2.20 to at least 104.8.0 to clear its 1 open critical-or-high vulnerability.
What is the latest version of Svelte?
The latest supported Svelte release is 5.56.3.
Is Svelte 4.2.20 still receiving security updates?
Yes — the 4.2 line is still supported and receiving security updates. The latest release is 5.56.3.
Informational only, from public data (NVD · CISA KEV · EPSS · endoflife.date), and can lag or miss vendor-specific fixes. Always confirm against Svelte's official advisory before you patch or upgrade — Svelte official site ↗