What is the CVSS score of CVE-2026-27119?

CVE-2026-27119 has a CVSS 3.1 base score of 5.4 (Medium). CVSS vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N. EPSS exploitation probability: 0.0%.

Which versions of Svelte are affected by CVE-2026-27119?

CVE-2026-27119 presents moderate security risk, a cross-site scripting vulnerability rated CVSS 5.4. Attackers could inject scripts to steal sessions or perform actions as authenticated users.. A patch is available.

How to fix or mitigate CVE-2026-27119?

Within 30 days: Identify affected systems and apply vendor patches as part of regular patch cycle. Verify Content-Security-Policy and output encoding.

Svelte CVE-2026-27119

MEDIUM

Cross-site Scripting (XSS) (CWE-79)

2026-02-20 security-advisories@github.com

GHSA-h7h7-mm68-gmrc

XSS Red Hat Svelte

5.4

CVSS 3.1 · GitHub Advisory

Severity by source

GitHub Advisory PRIMARY

5.4 MEDIUM

AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N

Red Hat

5.6 MEDIUM

qualitative

Primary rating from GitHub Advisory.

CVSS VectorGitHub Advisory

Attack Vector

Network

Attack Complexity

Low

Privileges Required

Low

User Interaction

Required

Scope

Changed

Confidentiality

Low

Integrity

Low

Availability

None

Lifecycle Timeline

Patch released

Mar 31, 2026 - 21:13 nvd

Patch available

Analysis Generated

Mar 12, 2026 - 22:04 vuln.today

CVE Published

Feb 20, 2026 - 23:16 nvd

MEDIUM 5.4

DescriptionGitHub Advisory

svelte performance oriented web framework. From 5.39.3, <=5.51.4, in certain circumstances, the server-side rendering output of an <option> element does not properly escape its content, potentially allowing HTML injection in the SSR output. Client-side rendering is not affected. This vulnerability is fixed in 5.51.5.

AnalysisAI

Improper HTML escaping in Svelte versions 5.39.3 through 5.51.4 allows HTML injection attacks through unescaped option element content during server-side rendering, enabling attackers to inject malicious HTML into SSR output. Client-side rendering is unaffected, and the vulnerability is limited to applications using vulnerable Svelte versions on the server. This medium-severity flaw requires upgrading to version 5.51.5 or later, as no patch is currently available for affected versions.

Technical ContextAI

Classified as CWE-79 (Cross-site Scripting (XSS)). Affects Svelte. svelte performance oriented web framework. From 5.39.3, <=5.51.4, in certain circumstances, the server-side rendering output of an <option> element does not properly escape its content, potentially allowing HTML injection in the SSR output. Client-side rendering is not affected. This vulnerability is fixed in 5.51.5.

RemediationAI

Fixed in version 5.51.5.. Implement output encoding and Content Security Policy headers. Restrict network access to the affected service where possible.