CVE-2026-33439

CRITICALNVD 9.89.8—
EchelonGraph scoreMEDIUM confidence

This critical-severity CVE scores 9.8 under NVD CVSS v3. EPSS exploit probability: 13.4%, top 6% 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
9.8
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS: 10%CVSS: 9.8Exploit: NoneExposed: 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)
EPSS
95.2%
KEV
Not listed

Published

April 7, 2026

Last Modified

April 15, 2026

Advisory Details (1)

Auto-updated Apr 29, 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 7× in last 7d / 33× 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. 2026-07-12 05:46 UTCEPSS rescore
  2. 2026-07-11 08:27 UTCEPSS rescore
  3. 2026-07-09 19:10 UTCEPSS rescore
  4. 2026-07-08 15:15 UTCEPSS rescore
  5. 2026-07-07 13:46 UTCEPSS rescore
  6. 2026-07-06 16:27 UTCEPSS rescore
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  8. 2026-07-05 02:30 UTCEPSS rescore
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  10. 2026-07-01 15:06 UTCEPSS rescore
  11. 2026-06-30 23:22 UTCEPSS rescore
  12. 2026-06-28 04:56 UTCEPSS rescore
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  15. 2026-06-25 13:49 UTCEPSS rescore
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  24. 2026-06-21 01:59 UTCEPSS rescore
  25. 2026-06-18 17:52 UTCEPSS rescore
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  1. 2026-06-18 17:52 UTCEPSS rescore
  2. 2026-06-17 17:53 UTCEPSS rescore
  3. 2026-06-16 17:52 UTCEPSS rescore
  4. 2026-06-15 17:49 UTCEPSS rescore
  5. 2026-06-14 23:18 UTCEPSS rescore
  6. 2026-06-13 23:00 UTCEPSS rescore
  7. 2026-06-12 23:12 UTCEPSS rescore
  8. 2026-06-12 23:12 UTCEPSS rescore
  9. 2026-06-12 04:55 UTCEG score recompute
  10. 2026-06-12 01:06 UTCEG score recompute
  11. 2026-06-11 21:16 UTCEG score recompute
  12. 2026-06-11 14:00 UTCEPSS rescore
  13. 2026-06-10 22:18 UTCEPSS rescore
  14. 2026-06-10 20:27 UTCEG score recompute
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  17. 2026-06-10 12:48 UTCEG score recompute
  18. 2026-06-10 08:47 UTCEG score recompute
  19. 2026-06-10 04:58 UTCEG score recompute
  20. 2026-06-10 01:08 UTCEG score recompute
  21. 2026-06-09 17:36 UTCEG score recompute
  22. 2026-06-09 13:46 UTCEG score recompute
  23. 2026-06-08 13:17 UTCEG score recompute
  24. 2026-06-08 09:28 UTCEG score recompute
  25. 2026-06-08 05:39 UTCEG score recompute
  26. 2026-06-08 01:49 UTCEG score recompute
  27. 2026-06-07 22:00 UTCEG score recompute
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  29. 2026-06-07 15:25 UTCEPSS rescore
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  31. 2026-06-07 15:25 UTCEPSS rescore
  32. 2026-06-07 14:16 UTCEG score recompute
  33. 2026-06-07 10:07 UTCEG score recompute
  34. 2026-06-06 13:47 UTCEPSS rescore
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  36. 2026-06-05 22:47 UTCEPSS rescore
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  38. 2026-06-04 13:12 UTCEPSS rescore
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  40. 2026-06-02 20:13 UTCEPSS rescore
  41. 2026-06-01 13:52 UTCEPSS rescore
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  44. 2026-05-31 22:30 UTCEPSS rescore
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  46. 2026-05-31 00:16 UTCEPSS rescore
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  49. 2026-05-29 13:44 UTCEPSS rescore
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  51. 2026-05-28 13:44 UTCEPSS rescore
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  54. 2026-05-27 13:40 UTCEPSS rescore
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  56. 2026-05-27 13:40 UTCEPSS rescore
  57. 2026-05-23 00:08 UTCEG score recompute
  58. 2026-05-20 22:38 UTCEPSS rescore
  59. 2026-05-20 22:38 UTCEPSS rescore
  60. 2026-05-20 11:22 UTCEPSS rescore
  61. 2026-05-20 11:22 UTCEPSS rescore
  62. 2026-05-20 07:59 UTCEG score recompute
  63. 2026-05-20 03:41 UTCEG score recompute
  64. 2026-05-19 23:16 UTCEG score recompute
  65. 2026-05-19 19:14 UTCEG score recompute
  66. 2026-05-19 14:59 UTCEG score recompute
  67. 2026-05-19 10:40 UTCEG score recompute
  68. 2026-05-19 05:58 UTCEG score recompute
  69. 2026-05-19 02:07 UTCEG score recompute

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 ↗

Related CVEs(same CWE)

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 April 15, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-33439 actively exploited?
CVE-2026-33439 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 95.2% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.
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

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