Svelte SSR does not validate dynamic element tag names in `<svelte:element>`
cve-program · CVE-2026-27122
Publishedsvelte 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.
Read the publisher's advisoryeuvd · EUVD-2026-7538
Publishedsvelte 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.
Read the publisher's advisorynvd · CVE-2026-27122
Publishedsvelte 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.
Read the publisher's advisoryosv · GHSA-m56q-vw4c-c2cp
PublishedWhen 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.
Read the publisher's advisoryAffected versions, risk and source history
Related advisories and sources
Publishers link these advisories through the identifiers shown below. A shared identifier or date alone does not tell you whether your software is affected or whether the advisories describe the same cause.
CVE-2026-27122 · CVE overview and exploitation status
cve-program · CVE-2026-27122
euvd · EUVD-2026-7538
nvd · CVE-2026-27122
osv · GHSA-m56q-vw4c-c2cp
Related changes
Linked by CVE identifierNo related changes are available here.