Summary
Togoder Security scanned the npm package js-yaml@4.3.2 on Oct 6, 2026. An AI review of 27 source files produced 2 low severity findings. No malicious behavior, install-time payloads, credential theft or exfiltration were identified.
Findings 2
Prototype pollution protection
NPS-80FC0B0E88AC
The setProperty function uses Object.defineProperty for the __proto__ key to protect against prototype pollution, consistent with the referenced GitHub issue.
Resource exhaustion protection
NPS-0B5A029D46DE
maxDepth and maxTotalMergeKeys limits mitigate denial-of-service via deeply nested structures or excessive merge keys.
Files reviewed
| File | Verdict | What the reviewer saw |
|---|---|---|
| bin/js-yaml.js | safe | No malicious patterns detected |
| index.js | safe | Cleared by Jev triage; no further analysis needed |
| lib/common.js | safe | Cleared by Jev triage; no further analysis needed |
| lib/dumper.js | safe | Cleared by Jev triage; no further analysis needed |
| lib/exception.js | safe | Cleared by Jev triage; no further analysis needed |
| lib/index_vite_proxy.tmp.mjs | safe | No malicious patterns detected |
| lib/loader.js | safe | This is the standard js-yaml loader with explicit prototype-pollution and resource-limit safeguards; no malicious patterns detected. |
| lib/schema.js | safe | Cleared by Jev triage; no further analysis needed |
| lib/schema/core.js | safe | Cleared by Jev triage; no further analysis needed |
| lib/schema/default.js | safe | No malicious patterns detected; the file only extends a YAML schema with standard type definitions. |
| lib/schema/failsafe.js | safe | No malicious patterns detected; this is a standard YAML Failsafe schema definition with only static local requires. |
| lib/schema/json.js | safe | Cleared by Jev triage; no further analysis needed |
| lib/snippet.js | safe | Cleared by Jev triage; no further analysis needed |
| lib/type.js | safe | Cleared by Jev triage; no further analysis needed |
| lib/type/binary.js | safe | Cleared by Jev triage; no further analysis needed |
| lib/type/bool.js | safe | Cleared by Jev triage; no further analysis needed |
| lib/type/float.js | safe | Cleared by Jev triage; no further analysis needed |
| lib/type/int.js | safe | Cleared by Jev triage; no further analysis needed |
| lib/type/map.js | safe | Cleared by Jev triage; no further analysis needed |
| lib/type/merge.js | safe | Cleared by Jev triage; no further analysis needed |
| lib/type/null.js | safe | Cleared by Jev triage; no further analysis needed |
| lib/type/omap.js | safe | Cleared by Jev triage; no further analysis needed |
| lib/type/pairs.js | safe | Cleared by Jev triage; no further analysis needed |
| lib/type/seq.js | safe | Cleared by Jev triage; no further analysis needed |
| lib/type/set.js | safe | Cleared by Jev triage; no further analysis needed |
Show 2 more files
| File | Verdict | What the reviewer saw |
|---|---|---|
| lib/type/str.js | safe | Cleared by Jev triage; no further analysis needed |
| lib/type/timestamp.js | safe | Cleared by Jev triage; no further analysis needed |
Affected version ranges
None of the 2 scanned versions of js-yaml are flagged high or critical. The latest scanned version, 4.3.2, is clean. Only versions we have scanned are listed; unscanned versions between them are not covered.
| Versions | Verdict | Count | Range | Top findings |
|---|---|---|---|---|
| 4.3.2 | No issues | 1 | 4.3.2 | |
| 4.1.1 – 4.3.0 | Not scanned | 2 | >=4.1.1 <=4.3.0 | |
| 4.1.0 | No issues | 1 | 4.1.0 | |
| 3.15.0 – 3.15.2 | Not scanned | 2 | >=3.15.0 <=3.15.2 |
Full list, including published versions not scanned yet: version ranges API.
Scanned versions of js-yaml
Frequently asked questions
Is js-yaml safe to use?
Our AI source review of js-yaml@4.3.2 found no malicious code: no install-time payloads, credential theft, exfiltration, obfuscated loaders or backdoors.
Does js-yaml contain malware?
No malware was identified in js-yaml@4.3.2 when Togoder Security scanned it on Oct 6, 2026. A new version can still introduce malicious code, so scan the exact versions in your lockfile.
How was js-yaml checked?
Togoder Security downloaded the published npm package and had an AI model read its 27 source files, looking for install scripts, credential access, network exfiltration, obfuscation, backdoors and crypto-wallet theft. The results are cached by file hash and shown here.
How do I scan js-yaml together with the rest of my dependencies?
Upload your lockfile at https://security.togoder.click/scan or call the API documented at https://security.togoder.click/api-docs. Files that have already been scanned, like the ones in js-yaml@4.3.2, cost nothing.