CVE-2026-53550

MEDIUMPre-NVD 5.35.3—
EchelonGraph scoreMEDIUM confidence

This medium-severity CVE scores 5.3 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit probability: 0.4%, top 69% 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
5.3EG
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 5.3Exploit: None knownExposed: 0

A fix is available — apply it.

js-yaml is a JavaScript YAML parser and dumper. Prior to 4.2.0 and 3.15.0, a crafted YAML document can trigger algorithmic CPU exhaustion in js-yaml merge-key processing (<<) by repeating the same alias many times in a merge sequence. This causes quadratic parse-time behavior relative to input size and can block a Node.js worker/event loop for seconds with a relatively small payload (tens of KB), resulting in denial of service. The issue is in merge handling inside lib/loader.js. This vulnerability is fixed in 4.2.0 and 3.15.0.

CVSS v3
5.3
EG Score
5.3(medium)
EG Risk
39(Track)
EG Risk 39/100SSVC: 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
Severity53% × 45%
Exploitation0% × 40%
Automatability100% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
31%
KEV
Not listed

Published

June 15, 2026

Last Modified

July 9, 2026

Advisory Details (1)

Auto-updated Jun 22, 2026
🔬 Proof of concept available. Patch available. Sources: github.
github Patch Available🟡 PoC Available

Quadratic-complexity DoS in merge key handling via repeated aliases · Advisory · nodeca/js-yaml · GitHub

https://github.com/nodeca/js-yaml/security/advisories/GHSA-h67p-54hq-rp68

Vendor Advisories for CVE-2026-53550(5)

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
redhatodf4/rook-ceph-rhel9-operator:17867068802026-08-18redhat
redhatnodejs22-main-22.23.1-2.1.hum12026-07-12redhat
redhatnodejs24-main-24.18.0-0.3.hum12026-07-11redhat
redhatnodejs25-main-25.9.0-1.3.hum12026-07-10redhat
redhatdotnet8-0-main-8.0.128-1.1.hum12026-07-10redhat
redhatnodejs26-main-26.4.0-1.3.hum12026-06-30redhat
redhatnodejs20-main-20.20.2-1.hum12026-04-21redhat

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

(5 across 5 ecosystems)
Debian:11(1)
PackageVulnerable rangeFixed inDependents
node-js-yaml3.14.1+dfsg+~3.12.6-2 ... 4.2.0+~4.0.9-1 (10 versions)——
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——
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——
Debian:14(1)
PackageVulnerable rangeFixed inDependents
node-js-yaml4.1.0+dfsg+~4.0.5-7, 4.1.1+dfsg+~4.0.9-14.2.0+~4.0.9-1—
npm(1)
PackageVulnerable rangeFixed inDependents
js-yaml—3.15.0—

Weakness Classification(1)

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

Additional Vendor Advisories

(3)

Vendors that published advisories for this CVE beyond the curated set above. Broader coverage but minimal per-row detail — click through for the original advisory.

Data Freshness Timeline

(refreshed 17× in last 7d / 71× 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.

Showing the most recent 100 of 127 total refreshes for this CVE.

  1. 2026-08-20 16:21 UTCEG score recompute
  2. 2026-08-20 16:21 UTCVendor advisory
  3. 2026-08-19 17:04 UTCEPSS rescore
  4. 2026-08-19 13:15 UTCEG score recompute
  5. 2026-08-19 13:15 UTCVendor advisory
  6. 2026-08-18 13:48 UTCEPSS rescore
  7. 2026-08-17 13:47 UTCEPSS rescore
  8. 2026-08-16 16:26 UTCEG score recompute
  9. 2026-08-16 16:26 UTCVendor advisory
  10. 2026-08-16 14:56 UTCEPSS rescore
  11. 2026-08-16 02:14 UTCEPSS rescore
  12. 2026-08-15 14:22 UTCEG score recompute
  13. 2026-08-15 14:22 UTCVendor advisory
  14. 2026-08-15 01:30 UTCEPSS rescore
  15. 2026-08-14 12:17 UTCEG score recompute
  16. 2026-08-14 12:17 UTCVendor advisory
  17. 2026-08-13 22:00 UTCEPSS rescore
  18. 2026-08-13 10:13 UTCEG score recompute
  19. 2026-08-13 10:13 UTCVendor advisory
  20. 2026-08-12 13:51 UTCEPSS rescore
  21. 2026-08-12 08:08 UTCEG score recompute
  22. 2026-08-12 08:08 UTCVendor advisory
  23. 2026-08-11 06:04 UTCEG score recompute
  24. 2026-08-11 06:04 UTCVendor advisory
  25. 2026-08-11 00:00 UTCEPSS rescore
Show 75 more
  1. 2026-08-10 03:59 UTCEG score recompute
  2. 2026-08-10 03:59 UTCVendor advisory
  3. 2026-08-09 13:46 UTCEPSS rescore
  4. 2026-08-09 01:55 UTCEG score recompute
  5. 2026-08-09 01:55 UTCVendor advisory
  6. 2026-08-08 16:37 UTCEPSS rescore
  7. 2026-08-07 23:51 UTCEG score recompute
  8. 2026-08-07 23:51 UTCVendor advisory
  9. 2026-08-06 21:48 UTCEG score recompute
  10. 2026-08-06 21:48 UTCVendor advisory
  11. 2026-08-06 13:47 UTCEPSS rescore
  12. 2026-08-05 19:43 UTCEG score recompute
  13. 2026-08-05 19:43 UTCVendor advisory
  14. 2026-08-05 19:17 UTCEPSS rescore
  15. 2026-08-04 16:51 UTCEG score recompute
  16. 2026-08-04 16:51 UTCVendor advisory
  17. 2026-08-04 15:10 UTCEPSS rescore
  18. 2026-08-04 10:39 UTCEPSS rescore
  19. 2026-08-03 14:44 UTCEG score recompute
  20. 2026-08-03 14:44 UTCVendor advisory
  21. 2026-08-03 10:36 UTCEPSS rescore
  22. 2026-08-02 12:22 UTCEG score recompute
  23. 2026-08-02 12:22 UTCVendor advisory
  24. 2026-08-02 02:27 UTCEPSS rescore
  25. 2026-08-01 10:14 UTCEG score recompute
  26. 2026-08-01 10:14 UTCVendor advisory
  27. 2026-08-01 04:16 UTCEPSS rescore
  28. 2026-07-31 08:10 UTCEG score recompute
  29. 2026-07-31 08:10 UTCVendor advisory
  30. 2026-07-30 16:28 UTCEPSS rescore
  31. 2026-07-30 06:05 UTCEG score recompute
  32. 2026-07-30 06:05 UTCVendor advisory
  33. 2026-07-30 01:30 UTCEPSS rescore
  34. 2026-07-29 04:01 UTCEG score recompute
  35. 2026-07-29 04:01 UTCVendor advisory
  36. 2026-07-28 15:37 UTCEPSS rescore
  37. 2026-07-28 01:54 UTCEG score recompute
  38. 2026-07-28 01:54 UTCVendor advisory
  39. 2026-07-26 20:13 UTCEG score recompute
  40. 2026-07-26 20:13 UTCVendor advisory
  41. 2026-07-26 14:54 UTCEPSS rescore
  42. 2026-07-25 14:18 UTCEPSS rescore
  43. 2026-07-24 14:18 UTCEPSS rescore
  44. 2026-07-23 14:18 UTCEPSS rescore
  45. 2026-07-23 03:19 UTCEG score recompute
  46. 2026-07-22 14:08 UTCEPSS rescore
  47. 2026-07-21 15:25 UTCEPSS rescore
  48. 2026-07-20 17:08 UTCEPSS rescore
  49. 2026-07-19 14:31 UTCEPSS rescore
  50. 2026-07-19 14:31 UTCEPSS rescore
  51. 2026-07-19 02:29 UTCEPSS rescore
  52. 2026-07-18 10:04 UTCEPSS rescore
  53. 2026-07-16 22:57 UTCVendor advisory
  54. 2026-07-16 17:03 UTCEPSS rescore
  55. 2026-07-15 17:17 UTCVendor advisory
  56. 2026-07-15 16:57 UTCEPSS rescore
  57. 2026-07-15 16:57 UTCEPSS rescore
  58. 2026-07-15 02:00 UTCEPSS rescore
  59. 2026-07-15 02:00 UTCEPSS rescore
  60. 2026-07-14 15:03 UTCVendor advisory
  61. 2026-07-13 22:31 UTCEPSS rescore
  62. 2026-07-13 12:59 UTCVendor advisory
  63. 2026-07-13 06:13 UTCEPSS rescore
  64. 2026-07-13 06:13 UTCEPSS rescore
  65. 2026-07-12 10:53 UTCVendor advisory
  66. 2026-07-12 05:46 UTCEPSS rescore
  67. 2026-07-11 08:40 UTCVendor advisory
  68. 2026-07-11 08:27 UTCEPSS rescore
  69. 2026-07-11 08:27 UTCEPSS rescore
  70. 2026-07-10 06:35 UTCVendor advisory
  71. 2026-07-09 19:10 UTCEPSS rescore
  72. 2026-07-09 19:10 UTCEPSS rescore
  73. 2026-07-09 04:29 UTCVendor advisory
  74. 2026-07-08 15:16 UTCEPSS rescore
  75. 2026-07-08 15:16 UTCEPSS rescore

Frequently asked(5)

What is CVE-2026-53550?
CVE-2026-53550 is a medium vulnerability published on June 15, 2026. js-yaml is a JavaScript YAML parser and dumper. Prior to 4.2.0 and 3.15.0, a crafted YAML document can trigger algorithmic CPU exhaustion in js-yaml merge-key processing (<<) by repeating the same alias many times in a merge sequence. This causes quadratic parse-time behavior relative to input size…
When was CVE-2026-53550 disclosed?
CVE-2026-53550 was first published in the National Vulnerability Database on June 15, 2026, with the most recent update on July 9, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-53550 actively exploited?
CVE-2026-53550 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 68.9% of all scored CVEs.
What is the CVSS score of CVE-2026-53550?
CVE-2026-53550 has a CVSS v3 base score of 5.3 (NVD).
How do I remediate CVE-2026-53550?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-53550, 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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