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Medium 5.4Published Feb 20, 2026

CVE-2026-27121svelte performance oriented web framework.

Updated under an hour ago ()

Does this affect you?

It affects svelte. Add what you run to find out whether that includes you.

No exploitation reported and no EPSS estimate yet.

svelte performance oriented web framework. Versions of svelte prior to 5.51.5 are vulnerable to cross-site scripting (XSS) during server-side rendering. When using spread syntax to render attributes from untrusted data, event handler properties are included in the rendered HTML output. If an application spreads user-controlled or external data as element attributes, an attacker can inject malicious event handlers that execute in victims' browsers. This vulnerability is fixed in 5.51.5.

CVSS
5.4 MEDIUM (v3.1, NVD)CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N
Weakness (CWE)
CWE-79
Known exploited
Not in CISA's KEV catalog
EPSS (exploitation in the next 30 days)
Not loaded for this CVE
Assigned by
Not given
NVD analysis
Analyzed
Record last updated
Jun 17, 2026
First seen by InfoSec Signals
Oct 9, 2026

Affected products

Affected products
svelte svelte
svelte:svelte
before 5.51.5
NVD

References

  • vendor-advisory

The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.

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