Resource exhaustion in Nodeca Js-Yaml
CVE-2026-59868
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.
Published · last modified .
CVSS v3 metric
CVSS v3 base score 5.3 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L.
EPSS exploit prediction
EPSS: 0.006 (49.3th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 49th percentile — 49.3% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.006 · newest: 0.006 · change: 0.000
Affected products
- Nodeca Js-Yaml — versions >= 5.0.0, < 5.2.0
Weakness classification (CWE)
References
- github.com/nodeca/js-yaml/security/advisories/GHSA-g796-fgmg-93mv (Exploit, Vendor Advisory)
- github.com/nodeca/js-yaml/commit/3105455b81dee69e0fd36e09ac0b2ccfdb54adc1 (Patch)
- github.com/nodeca/js-yaml/releases/tag/5.2.0 (Release Notes)
Frequently asked questions
- What is CVE-2026-59868?
- CVE-2026-59868 is a medium-severity vulnerability in Nodeca Js-Yaml, classified under Inefficient Algorithmic Complexity. CVSS score: 5.3/10. Published 2026-07-08.
- How severe is CVE-2026-59868?
- Medium severity. CVSS v3 base score is 5.3 out of 10.