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chore(deps): update dependency yaml to v2.8.3 [security] - #241

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Jul 24, 2026
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chore(deps): update dependency yaml to v2.8.3 [security]#241
japboy merged 1 commit into
v2026from
renovate/npm-yaml-vulnerability

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@renovate renovate Bot commented Jul 23, 2026

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This PR contains the following updates:

Package Change Age Confidence
yaml (source) 2.8.12.8.3 age confidence

yaml is vulnerable to Stack Overflow via deeply nested YAML collections

CVE-2026-33532 / GHSA-48c2-rrv3-qjmp

More information

Details

Parsing a YAML document with yaml may throw a RangeError due to a stack overflow.

The node resolution/composition phase uses recursive function calls without a depth bound. An attacker who can supply YAML for parsing can trigger a RangeError: Maximum call stack size exceeded with a small payload (~2–10 KB). The RangeError is not a YAMLParseError, so applications that only catch YAML-specific errors will encounter an unexpected exception type. Depending on the host application's exception handling, this can fail requests or terminate the Node.js process.

Flow sequences allow deep nesting with minimal bytes (2 bytes per level: one [ and one ]). On the default Node.js stack, approximately 1,000–5,000 levels of nesting (2–10 KB input) exhaust the call stack. The exact threshold is environment-dependent (Node.js version, stack size, call stack depth at invocation).

Note: the library's Parser (CST phase) uses a stack-based iterative approach and is not affected. Only the compose/resolve phase uses actual call-stack recursion.

All three public parsing APIs are affected: YAML.parse(), YAML.parseDocument(), and YAML.parseAllDocuments().

PoC
const YAML = require('yaml');

// ~10 KB payload: 5000 levels of nested flow sequences
const payload = '['.repeat(5000) + '1' + ']'.repeat(5000);

try {
  YAML.parse(payload);
} catch (e) {
  console.log(e.constructor.name); // RangeError (NOT YAMLParseError)
  console.log(e.message);          // Maximum call stack size exceeded
}

Test environment: Node.js v24.12.0, macOS darwin arm64

Version Nesting Depth Input Size Result
1.0.0 5,000 10,001 B RangeError
1.10.2 5,000 10,001 B RangeError
2.0.0 5,000 10,001 B RangeError
2.8.2 5,000 10,001 B RangeError
2.8.3 5,000 10,001 B YAMLParseError

Depth threshold on yaml 2.8.2:

Nesting Depth Input Size Result
500 1,001 B Parses successfully
1,000 2,001 B RangeError (threshold varies by stack size)
5,000 10,001 B RangeError

Severity

  • CVSS Score: 4.3 / 10 (Medium)
  • Vector String: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L

References

This data is provided by OSV and the GitHub Advisory Database (CC-BY 4.0).


Release Notes

eemeli/yaml (yaml)

v2.8.3

Compare Source

  • Add trailingComma ToString option for multiline flow formatting (#​670)
  • Catch stack overflow during node composition (1e84ebb)

v2.8.2

Compare Source

  • Serialize -0 as -0 (#​638)
  • Do not double newlines for empty map values (#​642)

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This PR was generated by Mend Renovate. View the repository job log.

@renovate renovate Bot added the dependencies Pull requests that update a dependency file label Jul 23, 2026
@renovate
renovate Bot force-pushed the renovate/npm-yaml-vulnerability branch from 20aab26 to 0e03f7e Compare July 23, 2026 08:37
@japboy
japboy merged commit bfc93bb into v2026 Jul 24, 2026
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@japboy
japboy deleted the renovate/npm-yaml-vulnerability branch July 24, 2026 08:35
japboy added a commit that referenced this pull request Jul 25, 2026
chore(deps): update dependency yaml to v2.8.3 [security]
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