CVE-2026-42567
High
Description
Svelte is a performance oriented web framework. From version 5.51.5 to before version 5.55.7, an internal regex in the Svelte runtime can take exponential time to test in <svelte:element this={tag}></svelte:element>. This issue has been patched in version 5.55.7.
SeverityHigh
CVSS7.5
Exploit probability—
Product
Svelte
PublishedJun 9, 2026
First seenJun 9, 2026
Weakness typeCWE-1333CWE-1333
How to fix
Update
- svelte svelte5.55.7 or later
- svelte5.55.7 or later
Affected products
| Product | Affected versions | Fixed in |
|---|---|---|
| svelte svelte | 5.51.5 ≤ v < 5.55.7 | 5.55.7 |
| sveltenpm | 5.51.5 ≤ v < 5.55.7 | 5.55.7 |
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