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TI-2026-21576 Aliases CVE-2026-27125GHSA-crpf-4hrx-3jrp

Svelte SSR attribute spreading includes inherited properties from prototype chain

Priority LOW 24CWE-915Published · Updated

Key facts

Attack vector
Network
Privileges required
Low
User interaction
None
Attack complexity
High
Attack requirements
Present
Impact type
Tampering
Confidentiality · integrity · availability
Low · Low · 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-915.

Summary

svelte performance oriented web framework. Prior to 5.51.5, in server-side rendering, attribute spreading on elements (e.g. <div {...attrs}>) enumerates inherited properties from the object's prototype chain rather than only own properties. In environments where Object.prototype has already been polluted — a precondition outside of Svelte's control — this can cause unexpected attributes to appear in SSR output or cause SSR to throw errors. Client-side rendering is not affected. This vulnerability is fixed in 5.51.5.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00434 37th percentileScored 2026-11-07
Fix Partial svelte (sveltejs): 5.51.5svelte (npm): 5.51.5Red Hat: 1 without a fix

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
None
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
sveltejssveltebefore 5.51.55.51.5Patch availableCNA
—svelte (npm)before 5.51.55.51.5Patch availableGHSA-crpf-4hrx-3jrp
  • svelte Vendorsveltejs Affected before 5.51.5 Fixed in 5.51.5 Patch available CNA
  • svelte (npm) Vendor— Affected before 5.51.5 Fixed in 5.51.5 Patch available GHSA-crpf-4hrx-3jrp

CPE configurations NVD · 1

CPEVersionsRoleVendor
cpe:2.3:a:svelte:svelte:*:*:*:*:*:node.js:*:*before 5.51.5Vulnerablesveltejs
  • cpe:2.3:a:svelte:svelte:*:*:*:*:*:node.js:*:* Versions before 5.51.5 Vulnerable ·sveltejs

Remediation

  • Fix · CNA svelte (sveltejs) Fixed in 5.51.5
  • Fix · GHSA-crpf-4hrx-3jrp svelte (npm) Fixed in 5.51.5 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-2026-27125
  2. 2026-10-03 Alias added: GHSA-crpf-4hrx-3jrp

References

Patch 1

Advisory 2

Other 2

  • TI-2024-30159 Potential mXSS vulnerability due to improper HTML escaping in svelte CVSS 3.1MEDIUM 6.1
  • TI-2025-13940 Svelte 5.46.0 - Hydratable Key Script-Breakout XSS (SSR) CVSS 4.0MEDIUM 5.3
  • 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
See all 12 →

Sources

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