Answer in brief
CVE-2026-73643 records a High severity (CVSS 7.5) vulnerability in js-yaml: Exponential parsing time in the flow collections leads to denial of service. The current sources do not mark it as known exploited. The current feed maps nodeca/js-yaml (generic), js-yaml (npm), js-yaml (npm). 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 7.5. 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 nodeca/js-yaml (generic), js-yaml (npm), js-yaml (npm). Check affected ranges and fixed versions before updating.
| Package | Affected range | Fixed version |
|---|---|---|
| nodeca/js-yamlgeneric | >= 5.0.0, < 5.2.2 | Not reported |
| js-yamlnpm | >=5.0.0,<=5.2.1 | 5.2.2 |
| js-yamlnpm | >=5.0.0 <5.2.2 | 5.2.2 |
Published upstream
Aug 13, 2026
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Aug 13, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Aug 13, 2026
js-yaml is a JavaScript YAML parser and dumper. From 5.0.0 until 5.2.2, parsing a small YAML document can take exponential time when an application calls load() or loadAll() on untrusted input. In src/parser/parser.ts, readFlowCollection uses restoreState and calls parseNode a second time when a flow-sequence entry is recognized as a key: value pair. If the key is a nested flow sequence of the same shape, every level is parsed twice, causing O(2^n) work and allowing an input under 200 bytes to keep one CPU busy for minutes, block the Node.js event loop, and stall the process. No anchors, aliases, merges, tags, or nondefault options are required. This issue is fixed in version 5.2.2.
Quoted source text, attributed separately from HOL analysis.
Answer in brief
CVE-2026-73643 records a High severity (CVSS 7.5) vulnerability in js-yaml: Exponential parsing time in the flow collections leads to denial of service. The current sources do not mark it as known exploited. The current feed maps nodeca/js-yaml (generic), js-yaml (npm), js-yaml (npm). 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 7.5. 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 nodeca/js-yaml (generic), js-yaml (npm), js-yaml (npm). Check affected ranges and fixed versions before updating.
| Package | Affected range | Fixed version |
|---|---|---|
| nodeca/js-yamlgeneric | >= 5.0.0, < 5.2.2 | Not reported |
| js-yamlnpm | >=5.0.0,<=5.2.1 | 5.2.2 |
| js-yamlnpm | >=5.0.0 <5.2.2 | 5.2.2 |
Published upstream
Aug 13, 2026
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Aug 13, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Aug 13, 2026
js-yaml is a JavaScript YAML parser and dumper. From 5.0.0 until 5.2.2, parsing a small YAML document can take exponential time when an application calls load() or loadAll() on untrusted input. In src/parser/parser.ts, readFlowCollection uses restoreState and calls parseNode a second time when a flow-sequence entry is recognized as a key: value pair. If the key is a nested flow sequence of the same shape, every level is parsed twice, causing O(2^n) work and allowing an input under 200 bytes to keep one CPU busy for minutes, block the Node.js event loop, and stall the process. No anchors, aliases, merges, tags, or nondefault options are required. This issue is fixed in version 5.2.2.
Quoted source text, attributed separately from HOL analysis.