Svelte vulnerabilities: known CVEs & security history
Svelte · Web / Framework · 13 tracked CVEs · 0 actively exploited · updated June 2026 · what is a CVE? →
This is the full list of known vulnerabilities (CVEs) across all Svelte release lines — 13 in total. A CVE here doesn't mean your version is affected — check Svelte's current status and the safe version to run.
Known Svelte CVEs
Actively-exploited and most-severe first. Open any CVE for full details.
| CVE | Severity | CVSS | EPSS | Year |
|---|---|---|---|---|
| CVE-2021-29261 | high | 7.8 | 1% | 2021 |
| CVE-2026-42567 | high | 7.5 | 0% | 2026 |
| CVE-2026-27125 | medium | 6.8 | 0% | 2026 |
| CVE-2026-42599 | medium | 6.1 | 0% | 2026 |
| CVE-2026-42573 | medium | 6.1 | 0% | 2026 |
| CVE-2026-27901 | medium | 6.1 | 0% | 2026 |
| CVE-2025-15265 | medium | 6.1 | 0% | 2026 |
| CVE-2026-27902 | medium | 5.4 | 0% | 2026 |
| CVE-2026-27122 | medium | 5.4 | 0% | 2026 |
| CVE-2026-27121 | medium | 5.4 | 0% | 2026 |
| CVE-2026-27119 | medium | 5.4 | 0% | 2026 |
| CVE-2024-45047 | medium | 5.4 | 0% | 2024 |
| CVE-2022-25875 | medium | 5.4 | 1% | 2022 |
Is my Svelte version affected?
The list above spans every release. To know whether your version is affected — and the minimum safe version to upgrade to — check it directly.
Check your Svelte version → · Monitor Svelte for new CVEs →
Svelte vulnerabilities — frequently asked
How many known vulnerabilities does Svelte have?
IsItPatched tracks 13 CVEs for Svelte. 0 are critical-severity and 2 high-severity. These span every release line — what matters is whether the version you run is affected.
Does Svelte have any actively-exploited vulnerabilities?
None of Svelte's tracked CVEs are currently in CISA's KEV catalog — but new ones can be added at any time, so keep your version current.
What is the most severe Svelte vulnerability?
Among tracked issues, CVE-2021-29261 (HIGH, CVSS 7.8) ranks highest.
Is Svelte safe to use?
It depends on the version. The latest supported Svelte release (5.56.3) clears the known issues; older versions may still be affected. Check the exact version you run for a verdict.
CVE data aggregated from NVD, CISA KEV and EPSS (FIRST.org). Related: Svelte security status · Svelte end-of-life · actively-exploited CVEs. Always verify against Svelte's advisories — see our disclaimer.