7.5

CVE-2026-59869: js-yaml: YAML merge-key chains can force quadratic CPU consumption

Analyzed
AliasesRHSA-2026:37532RHSA-2026:38304UBUNTU-CVE-2026-59869
Published 08-07-2026Last modified 09-07-2026

Vulnerability summary

CVE-2026-59869 is a high (CVSS 7.5) Inefficient Algorithmic Complexity vulnerability in nodeca js-yaml. EPSS estimates a 0.58% chance of exploitation in the next 30 days, higher than 48% of scored vulnerabilities. 1 public exploit is recorded.

Priority
Prioritisepublic exploit

Public exploit (GitHub, Date unknown)

Source freshness unavailable

How is this decided?
CVSS score
7.5/10
010
High · v3.1 (CVE.org)
EPSS score
0.58%
0%100%
Low · 0.00 pp in 30 days
KEVNot listedNot listed by any tracked catalog.
RansomwareNot flaggedNo ransomware use recorded.
Public exploits1github

Advisory lineage

Upstream 0 · Downstream 9 · Related 2
OPENSUSE-SU-2026:12070-1RHSA-2026:37534RHSA-2026:37577RHSA-2026:38187RHSA-2026:38236RHSA-2026:40415

Timeline

  1. 08-07-2026
    PublishedVulnerability first disclosed.
  2. 09-07-2026
    Last modifiedVulnerability information updated.

Description

js-yaml is a JavaScript YAML parser and dumper. From 3.0.0 before 3.15.0 and from 4.0.0 before 4.3.0, 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 versions 3.15.0 and 4.3.0.

CVSS metrics

8 scores · 8 sources · 1 version

EPSS trend

Probability

0.58%

Chance of exploitation in the next 30 days

Percentile

48%

Versus all other CVEs

30-day change

No change 0.00 pp

From 0.58% on 04-10-2026

04-10-202603-11-2026

Known exploited

Compare KEV catalogs
CISA KEV

Not in the CISA KEV catalog.

ENISA CNW

Not in the ENISA CNW catalog.

CIRCL

Not in the CIRCL catalog.

Public exploits

1 found
  • githubUnverified

    Js Yaml

    Maturity: poc

Weaknesses

CWE · root cause

Affected systems

Version check

Known conditions: network-reachable, no authentication, no user interaction (CVSS vector). Other conditions: not stated in public data.

Chainguard99 products
  • airflow-2All versions (No fix recorded)
  • airflow-core-2All versions (No fix recorded)
  • arangodb-3.12< 3.12.9.4-r15
  • argo-workflows-ui-4.0All versions (No fix recorded) | < 4.0.11-r0
  • authentik-2025.12All versions (No fix recorded)
Redhat18 products
  • nodejs22< 0:22.23.1-2.1.hum1
  • nodejs22-bin< 0:22.23.1-2.1.hum1
  • nodejs22-devel< 0:22.23.1-2.1.hum1
  • nodejs22-docs< 0:22.23.1-2.1.hum1
  • nodejs22-full-i18n< 0:22.23.1-2.1.hum1
Wolfi15 products
  • argo-workflows-ui-4.0All versions (No fix recorded) | < 4.0.11-r0
  • code-server< 4.130.0-r1
  • eslint< 10.8.0-r1
  • jupyter-base-notebook< 7.6.3-r2
  • katib-suggestion-hyperopt< 0.19.0-r40
Debian1 product
  • node-js-yamlAll versions (No fix recorded) | < 4.2.0+~4.0.9-2
Nodeca1 product
  • js-yaml≥ 3.0.0, < 3.15.0 | ≥ 4.0.0, < 4.3.0
Npm1 product
  • js-yaml≥ 3.0.0, < 3.15.0 | ≥ 4.0.0, < 4.3.0
Ubuntu1 product
  • node-js-yamlAll versions (No fix recorded)

7 vendors · 136 products

References

19 links
Show all 19 references