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.

Metrics

Attack Vector Network

Attack Complexity High

Privileges Required High

Attack Requirements Present

User Interaction None

Vulnerable System Confidentiality Impact Low

Vulnerable System Integrity Impact None

Vulnerable System Availability Impact None

Subsequent System Confidentiality Impact High

Subsequent System Integrity Impact High

Subsequent System Availability Impact None

Attack Vector Network

Attack Complexity Low

Privileges Required Low

Scope Changed

Confidentiality Impact Low

Integrity Impact Low

Availability Impact None

User Interaction Required

No CVSS v3.0

No CVSS v2

This CVE is not in the KEV list.

Exploitation none

Automatable no

Technical Impact partial

Affected Vendors & Products

Vendors Products
Svelte
  • Svelte

Configuration 1 [-]

cpe:2.3:a:svelte:svelte:*:*:*:*:*:node.js:*:*

No data.

References
Link Providers
https://www.spirityenterprise.com/pentest spirity
https://github.com/sveltejs/svelte/security/advisories/GHSA-m56q-vw4c-c2cp cve-icon cve-icon cve-icon
https://nvd.nist.gov/vuln/detail/CVE-2026-27122 cve-icon
https://www.cve.org/CVERecord?id=CVE-2026-27122 cve-icon
History

Mon, 23 Feb 2026 21:00:00 +0000

Type Values Removed Values Added
CPEs cpe:2.3:a:svelte:svelte:*:*:*:*:*:node.js:*:*
Metrics 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'}

 cvssV3_1

{'score': 5.4, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N'}

Mon, 23 Feb 2026 20:15:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Mon, 23 Feb 2026 15:00:00 +0000

Type Values Removed Values Added
First Time appeared Svelte
Svelte svelte
Vendors & Products Svelte
Svelte svelte

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'}
cve-icon MITRE

Status: PUBLISHED

Assigner: GitHub_M

Published:

Updated: 2026-02-23T19:23:03.403Z

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

Link: CVE-2026-27122

cve-icon Vulnrichment

Updated: 2026-02-23T19:22:53.632Z

cve-icon NVD

Status : Analyzed

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

Modified: 2026-02-23T20:53:01.857

Link: CVE-2026-27122

cve-icon Redhat

Severity : Moderate

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

Links: CVE-2026-27122 - Bugzilla