Read the docs
TI-2026-86711 Aliases CVE-2026-123569GHSA-hf27-79c5-2rv5

Resource exhaustion in devalue npm package via sparse arrays

Priority MEDIUM 53CWE-770Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
None
Attack complexity
Low
Attack requirements
None
Impact type
Denial of service
Confidentiality · integrity · availability
None · None · High
Fix status
Fixed

Attack profile from CVSS 4.0 · CNA. Fix status from CNA. Impact type from CWE-770.

Summary

The devalue npm package from sveltejs before 5.6.3 is affected. Missing limits on resource allocation (CWE-770) let serialization of sparse arrays with uneval or stringify consume excessive CPU and memory. A remote attacker without privileges who gets a sparse array created on the server and serialized there can cause a denial of service.

Written with Claude Haiku 5.5 from the sources below · 2026-11-08

Description from the CNA

The devalue package for npm before 5.6.3 can consume excessive CPU and memory when serializing sparse arrays with uneval or stringify. An attacker who manages to get a sparse array created on the server, which mainstream wire formats do not allow, and serialized there can cause a denial of service.

Why it matters now

Fix Fixed devalue (sveltejs): 5.6.3

SSVC decision points

Not available: CISA has not published SSVC decision points for this record.

Affected products

VendorProductAffected versionsFixed inStatusSource
sveltejsdevaluebefore 5.6.35.6.3Patch availableCNA
  • devalue Vendorsveltejs Affected before 5.6.3 Fixed in 5.6.3 Patch available CNA

CPE names Threatist (inferred) · 1

Inferred from how NVD named this product before; not given by a source.

CPEVersionsRoleVendor
cpe:2.3:a:svelte:devalue:*:*:*:*:*:*:*:*——sveltejs
  • cpe:2.3:a:svelte:devalue:*:*:*:*:*:*:*:* Versions — — ·sveltejs

Remediation

Upgrade the sveltejs devalue npm package to version 5.6.3, which fixes this flaw.

Written with Claude Haiku 5.5 from the sources below · 2026-11-08

  • Fix · CNA devalue (sveltejs) Fixed in 5.6.3

Fixed in the same release

Records fixed by the same vendor advisory or release, as the CNA lists them.

  • Release ·

    sveltejs devalue 5.6.3

    2 records Highest priority Priority MEDIUM 1 MEDIUM, 1 LOW

    Other records, highest priority first

    • TI-2026-86710 Prototype pollution in Sveltejs devalue via uneval outputPriority LOW 26
    Show all 2 records →

Timeline

  1. 2026-11-08 Threatist record created from CVE-2026-123569
  2. 2026-11-08 Alias added: GHSA-hf27-79c5-2rv5

References

Advisory 1

  • TI-2023-13469 SvelteKit framework has Insufficient CSRF protection for CORS requests CVSS 3.1HIGH 8.8
  • TI-2023-13464 SvelteKit has Insufficient Cross-Site Request Forgery Protection CVSS 3.1HIGH 8.8
  • TI-2024-15660 Sending a GET or HEAD request with a body crashes SvelteKit CVSS 3.1HIGH 7.5
  • TI-2024-30159 Potential mXSS vulnerability due to improper HTML escaping in svelte CVSS 3.1MEDIUM 6.1
  • TI-2025-23466 SvelteKit allows XSS via tracked search_params CVSS 3.1MEDIUM 5.4
  • TI-2025-13940 Svelte 5.46.0 - Hydratable Key Script-Breakout XSS (SSR) CVSS 4.0MEDIUM 5.3
See all 50 →

Sources

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