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

[backstage-goalie]

This PR contains the following updates:

Package	Change	Age	Confidence
yaml (source)	2.6.0 → 2.8.3
yaml (source)	2.8.2 → 2.8.3
yaml (source)	2.6.1 → 2.8.3
yaml (source)	2.7.0 → 2.8.3
yaml (source)	2.8.1 → 2.8.3
yaml (source)	2.4.1 → 2.8.3

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Warning

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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

• https://github.com/eemeli/yaml/security/advisories/GHSA-48c2-rrv3-qjmp
• https://nvd.nist.gov/vuln/detail/CVE-2026-33532
• https://github.com/eemeli/yaml/commit/1e84ebbea7ec35011a4c61bbb820a529ee4f359b
• https://github.com/eemeli/yaml
• https://github.com/eemeli/yaml/releases/tag/v1.10.3
• https://github.com/eemeli/yaml/releases/tag/v2.8.3

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

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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)

v2.8.1

Compare Source

• Preserve empty block literals (#​634)

v2.8.0

Compare Source

• Add node cache for faster alias resolution (#​612)
• Re-introduce compatibility with Node.js 14.6 (#​614)
• Add --merge option to CLI tool (#​611)
• Improve error for tag resolution error on null value (#​616)
• Allow empty string as plain scalar representation, for failsafe schema (#​616)
• docs: include cli example (#​617)

v2.7.1

Compare Source

• Do not allow seq with single-line collection value on same line with map key (#​603)
• Improve warning & avoid TypeError on bad YAML 1.1 nodes (#​610)

v2.7.0

Compare Source

The library is now available on JSR as @​eemeli/yaml and on deno.land/x as yaml. In addition to Node.js and browsers, it should work in Deno, Bun, and Cloudflare Workers.

• Use .ts extension in all relative imports (#​591)
• Ignore newline after block seq indicator as space before value (#​590)
• Require Node.js 14.18 or later (was 14.6) (#​598)

v2.6.1

Compare Source

• Do not strip :00 seconds from !!timestamp values (#​578, with thanks to @​qraynaud)
• Tighten regexp for JSON !!bool (#​587, with thanks to @​vra5107)
• Default to literal block scalar if folded would overflow (#​585)

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