CVE-2026-27121

MEDIUM EPSS 8.7%
Published Feb 20, 20264mo ago · Modified Jun 17, 20262w ago
5.1 CVSS 4.0
Medium
Find Similar
Published Feb 20, 2026 4mo ago
Last Modified Jun 17, 2026 2w ago

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.

CVSS Details

Base Score
5.1
Exploitability
—
Impact
—
Vector string
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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
Attack Vector Network
Attack Complexity High
Privileges Required High
User Interaction None
Scope X

Threat Intelligence

EPSS Exploit Probability
8.7% percentile
Exploit & Patch Status
No Known Exploit
No Patch Available

Weaknesses 1

CWE-79 Cross-site Scripting Injection

Affected Products 1

VendorProductVersionRange
sveltesvelte* <5.51.5

References 1

  • github.com https://github.com/sveltejs/svelte/security/advisories/GHSA-f7gr-6p89-r883
    Vendor Advisory

Remediation

No remediation data recorded yet

Check vendor advisories and the NVD entry for patch availability.