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.
Advisories
Source ID Title
Github GHSA Github GHSA GHSA-f7gr-6p89-r883 Svelte affected by cross-site scripting via spread attributes in Svelte SSR
Fixes

Solution

No solution given by the vendor.


Workaround

No workaround given by the vendor.

History

Sat, 21 Feb 2026 12:15:00 +0000

Type Values Removed Values Added
References
Metrics threat_severity

None

cvssV3_1

{'score': 5.6, 'vector': 'CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:L'}

threat_severity

Moderate


Fri, 20 Feb 2026 22:45:00 +0000

Type Values Removed Values Added
Description 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.
Title Svelte affected by cross-site scripting via spread attributes in Svelte SSR
Weaknesses CWE-79
References
Metrics cvssV4_0

{'score': 5.1, 'vector': 'CVSS:4.0/AV:N/AC:H/AT:P/PR:H/UI:N/VC:L/VI:N/VA:N/SC:H/SI:H/SA:N'}


Projects

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cve-icon MITRE

Status: PUBLISHED

Assigner: GitHub_M

Published:

Updated: 2026-02-20T22:27:36.103Z

Reserved: 2026-02-17T18:42:27.043Z

Link: CVE-2026-27121

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Received

Published: 2026-02-20T23:16:02.503

Modified: 2026-02-20T23:16:02.503

Link: CVE-2026-27121

cve-icon Redhat

Severity : Moderate

Publid Date: 2026-02-20T22:27:36Z

Links: CVE-2026-27121 - Bugzilla

cve-icon OpenCVE Enrichment

No data.

Weaknesses