CVE-2026-42599

MEDIUM EPSS 6.5%
Published Jun 9, 20263w ago · Modified Jun 17, 20262w ago
5.1 CVSS 4.0
Medium
Find Similar
Published Jun 9, 2026 3w ago
Last Modified Jun 17, 2026 2w ago

Description

Svelte is a performance oriented web framework. Prior to version 5.55.7, 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. Note that this vulnerability only triggers if the user's browser has JavaScript enabled but Svelte's hydration mechanism does not reach the vulnerable element before the event fires. This issue has been patched in version 5.55.7.

CVSS Details

Base Score
5.1
Exploitability
—
Impact
—
Vector string
CVSS:4.0/AV:N/AC:H/AT:P/PR:H/UI:N/VC:N/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
6.5% percentile
Exploit & Patch Status
No Known Exploit
No Patch Available

Weaknesses 1

CWE-79 Cross-site Scripting Injection

Affected Products 1

VendorProductVersionRange
sveltesvelte* <5.55.7

References 2

  • github.com https://github.com/sveltejs/svelte/releases/tag/svelte%405.55.7
    Release Notes
  • github.com https://github.com/sveltejs/svelte/security/advisories/GHSA-pr6f-5x2q-rwfp
    Vendor Advisory

Remediation

No remediation data recorded yet

Check vendor advisories and the NVD entry for patch availability.