Read the docs
TI-2025-13940 Aliases CVE-2025-15265GHSA-6738-r8g5-qwp3

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

Priority MEDIUM 57CWE-79Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
Passive
Attack complexity
Low
Attack requirements
None
Impact type
Cross-site scripting
Confidentiality · integrity · availability
None · None · None
Fix status
Partial Red Hat: 1 without a fix

Attack profile from CVSS 4.0 · CNA. Fix status from CNA, GitHub and Red Hat. Impact type from CWE-79.

Summary

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.

Why it matters now

Exploitation Proof of concept CISA SSVC · not in CISA KEV
EPSS 0.00346 28th percentileScored 2026-11-08
Public exploit Yes 1 exploit referenceTagged by NVD
Fix Partial Svelte (Svelte): 5.46.3svelte (npm): 5.46.4Red Hat: 1 without a fix

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
Poc
Automatable
No
Technical impact
Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
sveltejsSvelte5.46.0 to before 5.46.35.46.3Patch availableCNA
—svelte (npm)5.46.0 to before 5.46.45.46.4Patch availableGHSA-6738-r8g5-qwp3
  • Svelte Vendorsveltejs Affected 5.46.0 to before 5.46.3 Fixed in 5.46.3 Patch available CNA
  • svelte (npm) Vendor— Affected 5.46.0 to before 5.46.4 Fixed in 5.46.4 Patch available GHSA-6738-r8g5-qwp3

CPE configurations NVD · 1

CPEVersionsRoleVendor
cpe:2.3:a:svelte:svelte:*:*:*:*:*:node.js:*:*5.46.0 to before 5.46.3Vulnerablesveltejs
  • cpe:2.3:a:svelte:svelte:*:*:*:*:*:node.js:*:* Versions 5.46.0 to before 5.46.3 Vulnerable ·sveltejs

Remediation

  • Fix · CNA Svelte (Svelte) Fixed in 5.46.3
  • Fix · GHSA-6738-r8g5-qwp3 svelte (npm) Fixed in 5.46.4 Advisory →

Vendor assessments

Red Hat

Red Hat rating: Moderate. Red Hat's page for this CVE →

ProductStatusPlan or fix
Red Hat Build of Podman Desktop - Tech PreviewAffectedNo fix yet: Fix deferred

Timeline

  1. 2026-10-02 Threatist record created from CVE-2025-15265
  2. 2026-10-03 Alias added: GHSA-6738-r8g5-qwp3

References

Exploit 1

Advisory 2

Other 3

  • TI-2024-30159 Potential mXSS vulnerability due to improper HTML escaping in svelte CVSS 3.1MEDIUM 6.1
  • TI-2021-10070 The unofficial Svelte extension before 104.8.0 for Visual Studio Code allows attackers to… CVSS 3.1HIGH 7.8
  • TI-2022-09436 Cross-site scripting (XSS) in svelte CVSS 3.1MEDIUM 6.1
  • TI-2026-30847 Svelte: ReDoS in `<svelte:element>` Tag Validation CVSS 4.0MEDIUM 5.9
  • TI-2026-30853 Svelte: XSS via DOM Clobbering of Internal Framework State CVSS 4.0MEDIUM 5.3
  • TI-2026-22246 Svelte Vulnerable to XSS via HTML Comment Injection in SSR Error Boundary Hydration Markers CVSS 4.0MEDIUM 5.3
See all 12 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences