Answer in brief
CVE-2026-40345 records a High severity vulnerability in deepmerge-ts: Stack exhaustion when merging recursive object graphs. The current sources do not mark it as known exploited. The current feed maps RebeccaStevens/deepmerge-ts (generic), deepmerge-ts (npm), deepmerge-ts (npm). Check affected ranges and fixed versions before updating.
Analysis pending evidence review
HOL Guard separates source facts from reviewed analysis. See the methodology.
A CVSS score is not reported in the current record. 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 RebeccaStevens/deepmerge-ts (generic), deepmerge-ts (npm), deepmerge-ts (npm). Check affected ranges and fixed versions before updating.
| Package | Affected range | Fixed version |
|---|---|---|
| RebeccaStevens/deepmerge-tsgeneric | < 8.0.0 | Not reported |
| deepmerge-tsnpm | <8.0.0 | 8.0.0 |
| deepmerge-tsnpm | >=0 <8.0.0 | 8.0.0 |
Published upstream
Aug 20, 2026
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Aug 20, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Aug 17, 2026
deepmerge-ts is a typescript library providing functionality to deep merging of javascript objects. Prior to 8.0.0, the deepmerge, deepmergeCustom, deepmergeInto, and deepmergeIntoCustom APIs do not track visited objects or object pairs when recursively merging records. When two input values contain self-references at the same property path, the merge logic repeatedly revisits the same pair until Node.js raises RangeError: Maximum call stack size exceeded. Applications that merge attacker-controlled recursive object graphs can synchronously crash the affected process or cause repeated worker restarts. Plain JSON input alone cannot create the recursive graph required to trigger the issue. This issue is fixed in version 8.0.0.
Quoted source text, attributed separately from HOL analysis.