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
9.1EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0.4%CVSS: 9.1Exploit: Elevated riskExposed services: Not assessed

A fix is available — apply it.

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
9.1CRITICALmedium confidence
EG Risk
57
EG Risk 57/100

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%
EPSS PROB
0.4%
EPSS %ILE
29th
KEV
Not listed

Published

June 12, 2026

Last Modified

June 15, 2026

Advisory Details (1)

Auto-updated Aug 1, 2026
🔬 Proof of concept available. Patch available. Sources: github.
githubMentions a patch (unverified)🟡 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

Vendor Advisories for CVE-2026-53609(1)

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

Affected Packages

(1 across 1 ecosystem)
npm(1)
PackageVulnerable rangeFix by version rangeDependents
apostrophe—
  • every version up to 4.31.0: fixed in 4.31.0
—

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 8× in last 7d / 24× 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 154 total refreshes for this CVE.

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

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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 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 0.4% probability of exploitation in the next 30 days (29th percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-53609?
CVE-2026-53609 has a CVSS base score of 9.1 (a secondary CVSS source that NVD displays; NVD's own analysis pending).
How do I remediate CVE-2026-53609?
A fix for CVE-2026-53609 is available: update to the fixed version the vendor names in its advisory. The vendor advisories EchelonGraph has for CVE-2026-53609 are linked in the Vendor Advisories panel on this page.

Dependency Blast Radius

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