CVE-2026-59869

HIGHPre-NVD 7.57.5—
EchelonGraph scoreMEDIUM confidence

This high-severity CVE scores 7.5 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit probability: 0.4%, top 65% of all CVEs by exploit prediction. GitHub Security Advisory data not yet ingested — confidence will rise once GHSA publishes (typical lag: hours to days for open-source ecosystem CVEs; never for infrastructure-only CVEs).

Triggered by: NVD CVSS baseline
Sources: epss, secondary
Trending — 3 sources updated this weekElevated
7.5EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 7.5Exploit: Elevated riskExposed: 0

A fix is available — apply it.

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 v3
7.5
EG Score
7.5(medium)
EG Risk
65(Attend)
EG Risk 65/100SSVC: Attend

EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).

How it’s computed
Severity75% × 45%
Exploitation40% × 40%
Automatability100% × 15%
Action: Remediate soon — notable exploitation risk.
EPSS PROB
0%
EPSS %ILE
35%
KEV
Not listed

Published

July 8, 2026

Last Modified

July 13, 2026

Advisory Details (3)

Auto-updated Jul 8, 2026
🔬 Proof of concept available. Patch available. Sources: github_commit, github.
github Patch Available🟡 PoC Available

YAML merge-key chains can force quadratic CPU consumption in js-yaml · Advisory · nodeca/js-yaml · GitHub

https://github.com/nodeca/js-yaml/security/advisories/GHSA-52cp-r559-cp3m
github_commit

commit 59423c6f8cdc (nodeca/js-yaml)

Fix landed in nodeca/js-yaml commit 59423c6f8cdc — awaiting tagged release

https://github.com/nodeca/js-yaml/commit/59423c6f8cdc78742ac00e25a4dd39ef16b702e4
github_commit

commit 24f13e79ee13 (nodeca/js-yaml)

Fix landed in nodeca/js-yaml commit 24f13e79ee13 — awaiting tagged release

https://github.com/nodeca/js-yaml/commit/24f13e79ee1343a7e30bd6f6c9d9cdbf0ac9b2b7

Vendor Advisories for CVE-2026-59869(9)

These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.

Patch Availability(7)

Vendor / EcosystemFixed in / PatchReleasedSource
redhatdotnet8-0-main-8.0.128-1.2.hum12026-07-15redhat
redhatnodejs22-main-22.23.1-2.1.hum12026-07-12redhat
redhatnodejs24-main-24.18.0-0.3.hum12026-07-11redhat
redhatrust-main-1.97.0-1.1.hum12026-07-11redhat
redhatnodejs25-main-25.9.0-1.3.hum12026-07-10redhat
redhatnodejs26-main-26.4.0-1.4.hum12026-07-10redhat
redhatdotnet8-0-main-8.0.128-1.1.hum12026-07-10redhat

Patches are aggregated from vendor advisories (Red Hat, Microsoft, Cisco, GitHub) and package ecosystems (OSV, GHSA). Multiple rows for the same upstream release have been deduplicated.

Affected Packages

(1 across 1 ecosystem)
npm(1)
PackageVulnerable rangeFixed inDependents
js-yaml—4.3.0—

Weakness Classification(1)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

Data Freshness Timeline

(refreshed 18× in last 7d / 41× in last 30d)

Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.

  1. 2026-07-27 01:16 UTCEG score recompute
  2. 2026-07-27 01:16 UTCVendor advisory
  3. 2026-07-26 14:54 UTCEPSS rescore
  4. 2026-07-26 14:54 UTCEPSS rescore
  5. 2026-07-26 12:28 UTCEG score recompute
  6. 2026-07-26 12:28 UTCVendor advisory
  7. 2026-07-25 14:18 UTCEPSS rescore
  8. 2026-07-25 14:18 UTCEPSS rescore
  9. 2026-07-24 14:18 UTCEPSS rescore
  10. 2026-07-24 14:18 UTCEPSS rescore
  11. 2026-07-23 14:18 UTCEPSS rescore
  12. 2026-07-23 14:18 UTCEPSS rescore
  13. 2026-07-23 03:21 UTCEG score recompute
  14. 2026-07-22 14:08 UTCEPSS rescore
  15. 2026-07-22 14:08 UTCEPSS rescore
  16. 2026-07-21 15:25 UTCEPSS rescore
  17. 2026-07-21 15:25 UTCEPSS rescore
  18. 2026-07-20 17:08 UTCEPSS rescore
  19. 2026-07-19 14:31 UTCEPSS rescore
  20. 2026-07-19 02:29 UTCEPSS rescore
  21. 2026-07-18 10:04 UTCEPSS rescore
  22. 2026-07-17 04:35 UTCVendor advisory
  23. 2026-07-16 17:03 UTCEPSS rescore
  24. 2026-07-16 15:47 UTCVendor advisory
  25. 2026-07-16 02:59 UTCVendor advisory
Show 16 more
  1. 2026-07-15 16:57 UTCEPSS rescore
  2. 2026-07-15 16:57 UTCEPSS rescore
  3. 2026-07-15 14:11 UTCVendor advisory
  4. 2026-07-15 02:00 UTCEPSS rescore
  5. 2026-07-15 02:00 UTCEPSS rescore
  6. 2026-07-15 01:24 UTCVendor advisory
  7. 2026-07-13 22:31 UTCEPSS rescore
  8. 2026-07-13 06:13 UTCEPSS rescore
  9. 2026-07-13 06:13 UTCEPSS rescore
  10. 2026-07-12 05:46 UTCEPSS rescore
  11. 2026-07-11 08:27 UTCEPSS rescore
  12. 2026-07-11 08:27 UTCEPSS rescore
  13. 2026-07-09 19:10 UTCEPSS rescore
  14. 2026-07-09 19:10 UTCEPSS rescore
  15. 2026-07-08 15:46 UTCEG score recompute
  16. 2026-07-08 15:45 UTCMITRE cvelistV5first tracked

Related CVEs(same vendor + same CWE)

Frequently asked(5)

What is CVE-2026-59869?
CVE-2026-59869 is a high vulnerability published on July 8, 2026. 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…
When was CVE-2026-59869 disclosed?
CVE-2026-59869 was first published in the National Vulnerability Database on July 8, 2026, with the most recent update on July 13, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-59869 actively exploited?
CVE-2026-59869 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0% probability of exploitation in the next 30 days, which ranks it in the top 65.3% of all scored CVEs.
What is the CVSS score of CVE-2026-59869?
CVE-2026-59869 has a CVSS v3 base score of 7.5 (NVD).
How do I remediate CVE-2026-59869?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-59869, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

Dependency Blast Radius

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