CVE-2026-53609

CRITICALPre-NVD 9.19.1—
EchelonGraph scoreMEDIUM confidence

This critical-severity CVE scores 9.1 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit probability: 0.2%, top 85% 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
9.1
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS: 0%CVSS: 9.1Exploit: NoneExposed: 0

No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.

ApostropheCMS is an open-source Node.js content management system. In versions up to and including 4.30.0, apos.util.set() traverses dot-notation paths without sanitizing __proto__, allowing an authenticated editor to write arbitrary values to Object.prototype via the $pullAll patch operator. A confirmed gadget in publicApiCheck() causes this to bypass authorization on all piece-type REST API endpoints for every subsequent unauthenticated request, for the lifetime of the Node.js process. As of time of publication, no known patched versions are available.

CVSS v3
9.1
EG Score
9.1(medium)
EG Risk
57(Track)
EG Risk 57/100SSVC: 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
Severity91% × 45%
Exploitation40% × 40%
Automatability0% × 15%
Action: Routine — remediate on your standard cadence.
EPSS
14.8%
KEV
Not listed

Published

June 12, 2026

Last Modified

June 15, 2026

Advisory Details (1)

Auto-updated Jun 12, 2026
🔬 Proof of concept available. Patch available. Sources: github.
github Patch Available🟡 PoC Available

Server-Side Prototype Pollution in apos.util.set via patch operators leads to process-wide authorization bypass · Advisory · apostrophecms/apostrophe · GitHub

https://github.com/apostrophecms/apostrophe/security/advisories/GHSA-6h5j-32cf-4253

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 9× in last 7d / 46× 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. 2026-07-23 14:18 UTCEPSS rescore
  2. 2026-07-23 03:19 UTCEG score recompute
  3. 2026-07-22 14:08 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 14:31 UTCEPSS rescore
  8. 2026-07-19 02:29 UTCEPSS rescore
  9. 2026-07-18 10:04 UTCEPSS rescore
  10. 2026-07-16 17:03 UTCEPSS rescore
  11. 2026-07-15 16:57 UTCEPSS rescore
  12. 2026-07-15 16:57 UTCEPSS rescore
  13. 2026-07-15 02:00 UTCEPSS rescore
  14. 2026-07-15 02:00 UTCEPSS rescore
  15. 2026-07-13 22:31 UTCEPSS rescore
  16. 2026-07-13 06:13 UTCEPSS rescore
  17. 2026-07-13 06:13 UTCEPSS rescore
  18. 2026-07-12 05:46 UTCEPSS rescore
  19. 2026-07-11 08:27 UTCEPSS rescore
  20. 2026-07-11 08:27 UTCEPSS rescore
  21. 2026-07-09 19:10 UTCEPSS rescore
  22. 2026-07-09 19:10 UTCEPSS rescore
  23. 2026-07-08 15:16 UTCEPSS rescore
  24. 2026-07-08 15:16 UTCEPSS rescore
  25. 2026-07-07 13:46 UTCEPSS rescore
Show 39 more
  1. 2026-07-07 13:46 UTCEPSS rescore
  2. 2026-07-06 16:27 UTCEPSS rescore
  3. 2026-07-06 16:27 UTCEPSS rescore
  4. 2026-07-06 02:23 UTCEPSS rescore
  5. 2026-07-06 02:23 UTCEPSS rescore
  6. 2026-07-05 02:31 UTCEPSS rescore
  7. 2026-07-05 02:30 UTCEPSS rescore
  8. 2026-07-04 06:31 UTCEPSS rescore
  9. 2026-07-04 06:31 UTCEPSS rescore
  10. 2026-07-01 15:07 UTCEPSS rescore
  11. 2026-06-30 23:22 UTCEPSS rescore
  12. 2026-06-29 14:06 UTCEPSS rescore
  13. 2026-06-29 14:06 UTCEPSS rescore
  14. 2026-06-28 14:07 UTCEPSS rescore
  15. 2026-06-28 04:56 UTCEPSS rescore
  16. 2026-06-28 04:56 UTCEPSS rescore
  17. 2026-06-27 03:08 UTCEPSS rescore
  18. 2026-06-25 13:49 UTCEPSS rescore
  19. 2026-06-24 14:05 UTCEPSS rescore
  20. 2026-06-23 21:33 UTCEPSS rescore
  21. 2026-06-23 21:33 UTCEPSS rescore
  22. 2026-06-22 14:25 UTCEPSS rescore
  23. 2026-06-22 14:25 UTCEPSS rescore
  24. 2026-06-21 14:56 UTCEPSS rescore
  25. 2026-06-21 14:56 UTCEPSS rescore
  26. 2026-06-21 01:59 UTCEPSS rescore
  27. 2026-06-21 01:59 UTCEPSS rescore
  28. 2026-06-19 19:26 UTCEPSS rescore
  29. 2026-06-19 19:26 UTCEPSS rescore
  30. 2026-06-18 17:52 UTCEPSS rescore
  31. 2026-06-18 17:52 UTCEPSS rescore
  32. 2026-06-17 17:53 UTCEPSS rescore
  33. 2026-06-16 17:53 UTCEPSS rescore
  34. 2026-06-15 17:49 UTCEPSS rescore
  35. 2026-06-15 17:49 UTCEPSS rescore
  36. 2026-06-14 23:18 UTCEPSS rescore
  37. 2026-06-13 23:00 UTCEPSS rescore
  38. 2026-06-12 22:18 UTCEG score recompute
  39. 2026-06-12 22:17 UTCNVD updatefirst tracked

Frequently asked(5)

What is CVE-2026-53609?
CVE-2026-53609 is a critical vulnerability published on June 12, 2026. ApostropheCMS is an open-source Node.js content management system. In versions up to and including 4.30.0, apos.util.set() traverses dot-notation paths without sanitizing proto, allowing an authenticated editor to write arbitrary values to Object.prototype via the $pullAll patch operator. A…
When was CVE-2026-53609 disclosed?
CVE-2026-53609 was first published in the National Vulnerability Database on June 12, 2026, with the most recent update on June 15, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-53609 actively exploited?
CVE-2026-53609 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 14.8% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.
What is the CVSS score of CVE-2026-53609?
CVE-2026-53609 has a CVSS v3 base score of 9.1 (NVD).
How do I remediate CVE-2026-53609?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-53609, 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.

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