CVE-2026-84375

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 68% 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 — Patch released this week
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: None knownExposed: 0

A fix is available — apply it.

js-yaml is a JavaScript YAML parser and dumper. From 3.0.0 until 3.15.2 and 4.3.2, maxTotalMergeKeys in lib/js-yaml/loader.js and lib/loader.js does not count empty mapping sources while processing the merge key <<. An attacker can alias a large sequence of empty mappings into many merge targets, causing O(N * K) processing while totalMergeKeys remains unchanged and the configured resource limit is never reached. A relatively small YAML document can therefore cause prolonged CPU consumption in applications that parse untrusted YAML, and merge processing is enabled by default on these release lines. This issue is fixed in versions 3.15.2 and 4.3.2.

CVSS v3
7.5
EG Score
7.5(medium)
EG Risk
49(Track)
EG Risk 49/100SSVC: Track

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%
Exploitation0% × 40%
Automatability100% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
32%
KEV
Not listed

Published

September 1, 2026

Last Modified

September 9, 2026

Advisory Details (5)

Auto-updated Sep 1, 2026
🔬 Proof of concept available. Patch available. Sources: github, github_pr, github_commit.
github_commit

commit d90b6612a5a8 (nodeca/js-yaml)

Fix landed in nodeca/js-yaml commit d90b6612a5a8 — awaiting tagged release

https://github.com/nodeca/js-yaml/commit/d90b6612a5a84385bdcb556c44578eac76dc0f6b
github_commit

commit 6a8e05f9a485 (nodeca/js-yaml)

Fix landed in nodeca/js-yaml commit 6a8e05f9a485 — awaiting tagged release

https://github.com/nodeca/js-yaml/commit/6a8e05f9a485188ed730ac81e81ae221352ef480
github_commit

commit 3485bc06ff8a (nodeca/js-yaml)

Fix landed in nodeca/js-yaml commit 3485bc06ff8a — awaiting tagged release

https://github.com/nodeca/js-yaml/commit/3485bc06ff8a0251505f44a00414d90df2466639
github_pr

fix: count empty merge sources against maxTotalMergeKeys

Fix merged in nodeca/js-yaml PR #797 on 2026-08-26 — awaiting tagged release

https://github.com/nodeca/js-yaml/pull/797
github Patch Available🟡 PoC Available

maxTotalMergeKeys does not limit CPU use for empty merge sources · Advisory · nodeca/js-yaml · GitHub

https://github.com/nodeca/js-yaml/security/advisories/GHSA-2883-xcg3-v3hh

Vendor Advisories for CVE-2026-84375(6)

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

Patch Availability(5)

Vendor / EcosystemFixed in / PatchReleasedSource
redhatquay/quay-rhel8:17885618412026-09-09redhat
redhatgrafana13-1-main-13.1.3-0.5.hum12026-09-03redhat
redhatgrafana13-2-main-13.2.1-0.1.hum12026-09-03redhat
redhatgrafana12-4-main-12.4.9-0.5.hum12026-09-02redhat
redhatgrafana13-2-main-13.2.0-0.1.4.hum12026-09-02redhat

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

(3 across 3 ecosystems)
Debian:12(1)
PackageVulnerable rangeFixed inDependents
node-js-yaml4.1.0+dfsg+~4.0.5-7, 4.1.1+dfsg+~4.0.9-1, 4.2.0+~4.0.9-1, 4.2.0+~4.0.9-2, 4.3.2+~4.0.9-1——
Debian:13(1)
PackageVulnerable rangeFixed inDependents
node-js-yaml4.1.0+dfsg+~4.0.5-7, 4.1.1+dfsg+~4.0.9-1, 4.2.0+~4.0.9-1, 4.2.0+~4.0.9-2, 4.3.2+~4.0.9-1——
Debian:14(1)
PackageVulnerable rangeFixed inDependents
node-js-yaml4.1.0+dfsg+~4.0.5-7, 4.1.1+dfsg+~4.0.9-1, 4.2.0+~4.0.9-1, 4.2.0+~4.0.9-24.3.2+~4.0.9-1—

Weakness Classification(2)

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

Data Freshness Timeline

(refreshed 24× in last 7d / 35× 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. 2026-09-11 14:53 UTCEPSS rescore
  2. 2026-09-11 14:53 UTCEPSS rescore
  3. 2026-09-11 09:53 UTCEG score recompute
  4. 2026-09-11 09:53 UTCVendor advisory
  5. 2026-09-10 21:39 UTCEG score recompute
  6. 2026-09-10 21:39 UTCVendor advisory
  7. 2026-09-10 09:27 UTCVendor advisory
  8. 2026-09-09 21:10 UTCVendor advisory
  9. 2026-09-09 11:29 UTCVendor advisory
  10. 2026-09-08 23:18 UTCEG score recompute
  11. 2026-09-08 23:18 UTCVendor advisory
  12. 2026-09-08 22:01 UTCEPSS rescore
  13. 2026-09-08 06:39 UTCVendor advisory
  14. 2026-09-07 18:25 UTCEG score recompute
  15. 2026-09-07 18:25 UTCVendor advisory
  16. 2026-09-07 06:14 UTCVendor advisory
  17. 2026-09-06 18:00 UTCEG score recompute
  18. 2026-09-06 18:00 UTCVendor advisory
  19. 2026-09-06 13:48 UTCEPSS rescore
  20. 2026-09-06 05:49 UTCVendor advisory
  21. 2026-09-05 17:37 UTCEG score recompute
  22. 2026-09-05 17:37 UTCVendor advisory
  23. 2026-09-05 15:31 UTCEPSS rescore
  24. 2026-09-05 05:23 UTCVendor advisory
  25. 2026-09-04 17:12 UTCEG score recompute
Show 10 more
  1. 2026-09-04 17:12 UTCVendor advisory
  2. 2026-09-04 05:07 UTCEPSS rescore
  3. 2026-09-04 05:01 UTCVendor advisory
  4. 2026-09-03 16:46 UTCVendor advisory
  5. 2026-09-03 04:34 UTCEG score recompute
  6. 2026-09-02 16:20 UTCEG score recompute
  7. 2026-09-02 14:12 UTCEPSS rescore
  8. 2026-09-01 22:19 UTCEG score recompute
  9. 2026-09-01 21:48 UTCEG score recompute
  10. 2026-09-01 21:47 UTCMITRE cvelistV5first tracked

Frequently asked(5)

What is CVE-2026-84375?
CVE-2026-84375 is a high vulnerability published on September 1, 2026. js-yaml is a JavaScript YAML parser and dumper. From 3.0.0 until 3.15.2 and 4.3.2, maxTotalMergeKeys in lib/js-yaml/loader.js and lib/loader.js does not count empty mapping sources while processing the merge key <<. An attacker can alias a large sequence of empty mappings into many merge targets,…
When was CVE-2026-84375 disclosed?
CVE-2026-84375 was first published in the National Vulnerability Database on September 1, 2026, with the most recent update on September 9, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-84375 actively exploited?
CVE-2026-84375 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 68.1% of all scored CVEs.
What is the CVSS score of CVE-2026-84375?
CVE-2026-84375 has a CVSS v3 base score of 7.5 (NVD).
How do I remediate CVE-2026-84375?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-84375, 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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