CVSS 4.0
5.1 mediumCVSS:4.0/AV:N/AC:H/AT:P/PR:H/UI:N/VC:L/VI:N/VA:N/SC:H/SI:H/SA:NCVE-2026-27121
Medium (5.1) in svelte svelte. EPSS 0.2% chance of exploitation in the next 30 days. Fixed in svelte 5.51.5.
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.
Severity
CVSS 3.1
5.4 mediumCVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N- EPSS
- 0.2% chance of exploitation in the next 30 days; higher than 12% of CVEs (scores of 2026-10-31)
- CWE
- CWE-79
- Published
- Modified
- Record from
- the NVD, synced
Affected
- svelte:svelte
Packages (OSV)
| Advisory | Ecosystem | Package | Affected | Fixed in |
|---|---|---|---|---|
| GHSA-f7gr-6p89-r883 | npm | svelte | <5.51.5 | 5.51.5 |