CVE-2026-53550

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Source
https://cve.org/CVERecord?id=CVE-2026-53550
Import Source
https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-53550.json
JSON Data
https://api.osv.dev/v1/vulns/CVE-2026-53550
Aliases
Downstream
Related
Published
2026-06-22T14:59:14.906Z
Modified
2026-07-11T04:04:11.025541924Z
Severity
  • 5.3 (Medium) CVSS_V3 - CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L CVSS Calculator
Summary
js-yaml: Quadratic-complexity DoS in merge key handling via repeated aliases
Details

js-yaml is a JavaScript YAML parser and dumper. Prior to 4.2.0 and 3.15.0, a crafted YAML document can trigger algorithmic CPU exhaustion in js-yaml merge-key processing (<<) by repeating the same alias many times in a merge sequence. This causes quadratic parse-time behavior relative to input size and can block a Node.js worker/event loop for seconds with a relatively small payload (tens of KB), resulting in denial of service. The issue is in merge handling inside lib/loader.js. This vulnerability is fixed in 4.2.0 and 3.15.0.

Database specific 
{
    "cna_assigner": "GitHub_M",
    "cwe_ids": [
        "CWE-407"
    ],
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/53xxx/CVE-2026-53550.json"
}
References

Affected packages

Git / github.com/nodeca/js-yaml

Affected ranges

Type
GIT
Repo
https://github.com/nodeca/js-yaml
Events
Introduced
0 Unknown introduced commit / All previous commits are affected
Fixed
c34b6c40027a769eb0d67958ae615268a1d55f54
Introduced
ee74ce4b4800282b2f23b776be7dc95dfe34db1c
Fixed
590dbabadd172b099c07654fab2eabec8c7a07b9
Database specific 
{
    "extracted_events": [
        {
            "introduced": "0"
        },
        {
            "fixed": "3.15.0"
        },
        {
            "introduced": "4.0.0"
        },
        {
            "fixed": "4.2.0"
        }
    ],
    "cpe": "cpe:2.3:a:nodeca:js-yaml:*:*:*:*:*:node.js:*:*",
    "source": "CPE_RANGE"
}

Affected versions

0.*
0.1.0
0.2.0
0.2.1
0.2.2
0.3.2
0.3.3
0.3.4
0.3.5
0.3.7
1.*
1.0.0
1.0.1
1.0.2
1.0.3
2.*
2.0.0
2.0.1
2.0.2
2.0.3
2.0.4
2.0.5
2.1.0
2.1.1
2.1.2
2.1.3
3.*
3.0.0
3.0.1
3.0.2
3.1.0
3.10.0
3.11.0
3.12.0
3.12.1
3.12.2
3.13.0
3.13.1
3.14.0
3.14.1
3.14.2
3.2.0
3.2.1
3.2.2
3.2.3
3.2.4
3.2.5
3.2.6
3.2.7
3.3.0
3.3.1
3.4.0
3.4.1
3.4.2
3.4.3
3.4.4
3.4.5
3.4.6
3.5.0
3.5.1
3.5.2
3.5.3
3.5.4
3.5.5
3.6.0
3.6.1
3.7.0
3.8.0
3.8.1
3.8.2
3.8.3
3.8.4
3.9.0
3.9.1
4.*
4.0.0
4.1.0
4.1.1

Database specific

source 
"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-53550.json"