Answer in brief
CVE-2026-126407 records a Medium severity (CVSS 5.9) vulnerability in Wasmtime before 36.0.20 Denial of Service via Borrowed Resource Transfer. The current sources do not mark it as known exploited. The current feed maps bytecodealliance/wasmtime (generic), bytecodealliance/wasmtime (generic), bytecodealliance/wasmtime (generic), bytecodealliance/wasmtime (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 5.9. 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 bytecodealliance/wasmtime (generic), bytecodealliance/wasmtime (generic), bytecodealliance/wasmtime (generic), bytecodealliance/wasmtime (generic). Check affected ranges and fixed versions before updating.
| Package | Affected range | Fixed version |
|---|---|---|
| bytecodealliance/wasmtimegeneric | >=0 <36.0.20 | 36.0.20 |
| bytecodealliance/wasmtimegeneric | >=37.0.0 <48.0.8 | 48.0.8 |
| bytecodealliance/wasmtimegeneric | >=49.0.0 <49.0.5 | 49.0.5 |
| bytecodealliance/wasmtimegeneric | >=50.0.0 <50.0.1 | 50.0.1 |
Published upstream
Nov 13, 2026
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Nov 13, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Nov 13, 2026
Wasmtime before 36.0.20, 37.0.0 before 48.0.8, 49.0.0 before 49.0.5, and 50.0.0 before 50.0.1 allocates untracked host memory when a component receives a borrow of a resource it defines itself, bypassing the per-store handle limit. A malicious guest component can repeatedly transfer such borrowed resources to consume arbitrary host memory, causing denial of service.
Quoted source text, attributed separately from HOL analysis.