CVE-2026-33439

CRITICALNVD 9.89.8—
EchelonGraph scoreMEDIUM confidence

This critical-severity CVE scores 9.8 under NVD CVSS v3. EPSS exploit probability: 10.5%, top 5% 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, nvd
Elevated
9.8EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 10%CVSS: 9.8Exploit: Elevated riskExposed: 0

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

Open Access Management (OpenAM) is an access management solution. Prior to 16.0.6, OpenIdentityPlatform OpenAM is vulnerable to pre-authentication Remote Code Execution (RCE) via unsafe Java deserialization of the jato.clientSession HTTP parameter. This bypasses the WhitelistObjectInputStream mitigation that was applied to the jato.pageSession parameter after CVE-2021-35464. An unauthenticated attacker can achieve arbitrary command execution on the server by sending a crafted serialized Java object as the jato.clientSession GET/POST parameter to any JATO ViewBean endpoint whose JSP contains tags (e.g., the Password Reset pages). This vulnerability is fixed in 16.0.6.

CVSS v3
9.8
EG Score
9.8(medium)
EG Risk
75(Track)
EG Risk 75/100SSVC: 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
Severity98% × 45%
Exploitation40% × 40%
Automatability100% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
10%
EPSS %ILE
95%
KEV
Not listed

Published

April 7, 2026

Last Modified

July 24, 2026

Advisory Details (1)

Auto-updated Aug 22, 2026
Patch available. Sources: github.
github Patch Available

Pre-Authentication Remote Code Execution via `jato.clientSession` Deserialization in OpenAM · Advisory · OpenIdentityPlatform/OpenAM · GitHub

https://github.com/OpenIdentityPlatform/OpenAM/security/advisories/GHSA-2cqq-rpvq-g5qj

Affected Packages

(1 across 1 ecosystem)
Maven(1)
PackageVulnerable rangeFixed inDependents
org.openidentityplatform.openam:openam14.5.2 ... 16.0.5 (38 versions)16.0.6—

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 6× in last 7d / 37× 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 129 total refreshes for this CVE.

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

Publicly available exploits

(2 references)

Working exploit code is in the public domain (1 GitHub PoC). Defenders should treat patch urgency accordingly — public PoCs typically lead to mass-exploitation within 24-72 hours.

  • GitHub PoCTheMalwareGuardian/CVE-2026-33439
    First seen Apr 30, 2026

    First publicly shared exploit implementation for CVE-2026-33439 (OpenAM pre-auth RCE via jato.clientSession deserialization).

    Open source ↗
  • Nucleihttp/cves/2026/CVE-2026-33439.yaml
    First seen Jan 1, 2026

    OpenAM <= 16.0.5 - Pre-Auth RCE via jato.clientSession Deserialization

    Open source ↗

Frequently asked(5)

What is CVE-2026-33439?
CVE-2026-33439 is a critical vulnerability published on April 7, 2026. Open Access Management (OpenAM) is an access management solution. Prior to 16.0.6, OpenIdentityPlatform OpenAM is vulnerable to pre-authentication Remote Code Execution (RCE) via unsafe Java deserialization of the jato.clientSession HTTP parameter. This bypasses the WhitelistObjectInputStream…
When was CVE-2026-33439 disclosed?
CVE-2026-33439 was first published in the National Vulnerability Database on April 7, 2026, with the most recent update on July 24, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-33439 actively exploited?
CVE-2026-33439 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 10% probability of exploitation in the next 30 days, which ranks it in the top 4.7% of all scored CVEs.
What is the CVSS score of CVE-2026-33439?
CVE-2026-33439 has a CVSS v3 base score of 9.8 (NVD).
How do I remediate CVE-2026-33439?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-33439, 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

See which npm, PyPI, Go, and Maven packages are affected by CVE-2026-33439

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