medium5.3
CVE-2026-59868
js-yaml: YAML merge-key chains can force quadratic CPU consumption in js-yaml
Impact
js-yaml is a JavaScript YAML parser and dumper. From 5.0.0 before 5.2.0, when merge keys are enabled, js-yaml can spend quadratic CPU time parsing a document whose size grows only linearly when a chain of mappings uses merge keys where each mapping merges the previous one. This issue is fixed in version 5.2.0.
Affected packages
| Ecosystem | Package | Affected | Fixed in |
|---|---|---|---|
| npm | js-yaml | >= 5.0.0, <= 5.1.0 | 5.2.0 |
Affected products
| Vendor | Product | Affected versions |
|---|---|---|
| Nodeca | Js-Yaml | from 5.0.0 before 5.2.0 |
Weakness classification
References
- NVD record
- CVE.org record
- GitHub advisory
- https://github.com/advisories/GHSA-g796-fgmg-93mv
- https://github.com/nodeca/js-yaml/security/advisories/GHSA-g796-fgmg-93mv
- https://nvd.nist.gov/vuln/detail/CVE-2026-59868
- https://github.com/nodeca/js-yaml/commit/3105455b81dee69e0fd36e09ac0b2ccfdb54adc1
- https://github.com/nodeca/js-yaml/releases/tag/5.2.0