CVE-2025-15265

Svelte 5.46.0 - Hydratable Key Script-Breakout XSS (SSR)

Published Jan 15, 2026 CVSS 4.0 · 5.3 Medium EPSS < 1% KEV · Not listed
Description
An SSR XSS exists in async hydration when attacker‑controlled keys are passed to hydratable. The key is embedded inside a <script> block without HTML‑safe escaping, allowing </script> to terminate the script and inject arbitrary JavaScript. This enables remote script execution in users' browsers, with potential for session theft and account compromise.
This issue affects Svelte: from 5.46.0 before 5.46.3.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

Source ID Title
Github GHSA Github GHSA GHSA-6738-r8g5-qwp3 svelte vulnerable to Cross-site Scripting
History
Type Values Removed Values Added
CPEs cpe:2.3:a:svelte:svelte:*:*:*:*:*:node.js:*:*
Type Values Removed Values Added
References
Metrics threat_severity

None

cvssV3_1

{'score': 6.1, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N'}

threat_severity

Moderate

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'poc', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Type Values Removed Values Added
Description An SSR XSS exists in async hydration when attacker‑controlled keys are passed to hydratable. The key is embedded inside a <script> block without HTML‑safe escaping, allowing </script> to terminate the script and inject arbitrary JavaScript. This enables remote script execution in users' browsers, with potential for session theft and account compromise. This issue affects Svelte: from 5.46.0 before 5.46.3.
Title Svelte 5.46.0 - Hydratable Key Script-Breakout XSS (SSR)
First Time appeared Svelte
Svelte svelte
Weaknesses CWE-79
CPEs cpe:2.3:a:svelte:svelte:*:*:linux:*:*:*:*:*
cpe:2.3:a:svelte:svelte:*:*:macos:*:*:*:*:*
cpe:2.3:a:svelte:svelte:*:*:windows:*:*:*:*:*
Vendors & Products Svelte
Svelte svelte
References
Metrics cvssV4_0

{'score': 5.3, 'vector': 'CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
Fluid Attacks
Published
Updated
Jan 15, 2026, 8:28 PM
Reserved
Dec 29, 2025, 3:31 PM
Status
Analyzed
Published
Jan 15, 2026, 8:16 PM
Modified
Jun 17, 2026, 8:37 AM
Severity
Moderate
Public date
Jan 15, 2026, 7:59 PM