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 71% 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
Elevated
7.5
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS: 0%CVSS: 7.5Exploit: NoneExposed: 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)
EPSS
29.5%
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(8)

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

Patch Availability(6)

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

Weakness Classification(1)

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

Data Freshness Timeline

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

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 29.5% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.
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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