Answer in brief
CVE-2026-123569 records a High severity (CVSS 8.7) vulnerability in Devalue before 5.6.3 Denial of Service via Sparse Array Serialization. The current sources do not mark it as known exploited. The current feed maps sveltejs/devalue (generic). Check affected ranges and fixed versions before updating.
Analysis pending evidence review
HOL Guard separates source facts from reviewed analysis. See the methodology.
CVSS is 8.7. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.
Analysis status
Analysis pending evidence review
Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.
The current feed maps sveltejs/devalue (generic). Check affected ranges and fixed versions before updating.
| Package | Affected range | Fixed version |
|---|---|---|
| sveltejs/devaluegeneric | >=0 <5.6.3 | 5.6.3 |
Published upstream
Nov 8, 2026
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Nov 8, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Nov 8, 2026
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.
Quoted source text, attributed separately from HOL analysis.