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Update dependency yaml to v2.8.3 [SECURITY]#1402

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haines merged 3 commits intomainfrom
renovate/npm-yaml-vulnerability
Mar 27, 2026
Merged

Update dependency yaml to v2.8.3 [SECURITY]#1402
haines merged 3 commits intomainfrom
renovate/npm-yaml-vulnerability

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@renovate renovate Bot commented Mar 27, 2026

This PR contains the following updates:

Package Change Age Adoption Passing Confidence
yaml (source) 2.8.22.8.3 age adoption passing confidence

GitHub Vulnerability Alerts

CVE-2026-33532

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

Release Notes

eemeli/yaml (yaml)

v2.8.3

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Signed-off-by: renovate[bot] <29139614+renovate[bot]@users.noreply.github.com>
@renovate renovate Bot requested a review from haines March 27, 2026 01:27
haines added 2 commits March 27, 2026 08:47
Signed-off-by: Andrew Haines <haines@cerbos.dev>
Signed-off-by: Andrew Haines <haines@cerbos.dev>
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renovate Bot commented Mar 27, 2026

Edited/Blocked Notification

Renovate will not automatically rebase this PR, because it does not recognize the last commit author and assumes somebody else may have edited the PR.

You can manually request rebase by checking the rebase/retry box above.

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@haines haines merged commit 0721a5a into main Mar 27, 2026
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@haines haines deleted the renovate/npm-yaml-vulnerability branch March 27, 2026 08:53
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