svelte performance oriented web framework. Prior to 5.51.5, when using <svelte:element this={tag}> in server-side rendering, the provided tag name is not validated or sanitized before being emitted into the HTML output. If the tag string contains unexpected characters, it can result in HTML injection in the SSR output. Client-side rendering is not affected. This vulnerability is fixed in 5.51.5.
Advisories
Source ID Title
Github GHSA Github GHSA GHSA-m56q-vw4c-c2cp Svelte SSR does not validate dynamic element tag names in `<svelte:element>`
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
Weaknesses CWE-1286
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. Prior to 5.51.5, when using <svelte:element this={tag}> in server-side rendering, the provided tag name is not validated or sanitized before being emitted into the HTML output. If the tag string contains unexpected characters, it can result in HTML injection in the SSR output. Client-side rendering is not affected. This vulnerability is fixed in 5.51.5.
Title Svelte SSR does not validate dynamic element tag names in `<svelte:element>`
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: 2026-02-20T22:28:37.824Z

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

Link: CVE-2026-27122

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Received

Published: 2026-02-20T23:16:02.640

Modified: 2026-02-20T23:16:02.640

Link: CVE-2026-27122

cve-icon Redhat

Severity : Moderate

Publid Date: 2026-02-20T22:28:37Z

Links: CVE-2026-27122 - Bugzilla

cve-icon OpenCVE Enrichment

No data.

Weaknesses