Inefficient Algorithmic Complexity Affecting org.webjars.npm:js-yaml package, versions [0,]
Threat Intelligence
Snyk has a proof-of-concept or detailed explanation of how to exploit this vulnerability.
The probability is the direct output of the EPSS model, and conveys an overall sense of the threat of exploitation in the wild. The percentile measures the EPSS probability relative to all known EPSS scores. Note: This data is updated daily, relying on the latest available EPSS model version. Check out the EPSS documentation for more details.
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Test your applications- Snyk IDSNYK-JAVA-ORGWEBJARSNPM-18313071
- published26 Jul 2026
- disclosed24 Jul 2026
- creditAlicia Sykes
Introduced: 24 Jul 2026
NewCVE-2026-73643 (opens in a new tab)How to fix?
A fix was pushed into the master branch but not yet published.
Overview
org.webjars.npm:js-yaml is a human-friendly data serialization language.
Affected versions of this package are vulnerable to Inefficient Algorithmic Complexity in the readFlowCollection function of parser.ts, which reaches exponential time when a flow sequence entry turns out to be a key: value pair and the parser rewinds to parse that entry a second time as the key. An attacker can exhaust CPU and block the Node event loop by supplying a small YAML document, under 200 bytes, with deeply nested flow sequences of key: value entries, since the re-parsing makes the work grow as O(2^n) in nesting depth. Exploitation occurs under the default configuration when the application parses untrusted YAML with load() or loadAll(), and needs no special schema, anchors, aliases, or merge keys.