CVE-2026-39890

CRITICALNVD 9.89.8—
EchelonGraph scoreMEDIUM confidence

This critical-severity CVE scores 9.8 under NVD CVSS v3. EPSS exploit probability: 0.6%, top 31% 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: 1%CVSS: 9.8Exploit: NoneExposed: 0

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

PraisonAI is a multi-agent teams system. Prior to 4.5.115, the AgentService.loadAgentFromFile method uses the js-yaml library to parse YAML files without disabling dangerous tags (such as !!js/function and !!js/undefined). This allows an attacker to craft a malicious YAML file that, when parsed, executes arbitrary JavaScript code. An attacker can exploit this vulnerability by uploading a malicious agent definition file via the API endpoint, leading to remote code execution (RCE) on the server. This vulnerability is fixed in 4.5.115.

CVSS v3
9.8
EG Score
9.8(medium)
EPSS
43.6%
KEV
Not listed

Published

April 8, 2026

Last Modified

April 15, 2026

Advisory Details (1)

Auto-updated May 1, 2026
🔬 Proof of concept available. Patch available. Sources: github.
github Patch Available🟡 PoC Available

Remote Code Execution via YAML Deserialization in Agent Definition Loading · Advisory · MervinPraison/PraisonAI · GitHub

https://github.com/MervinPraison/PraisonAI/security/advisories/GHSA-32vr-5gcf-3pw2

Affected Packages

(1 across 1 ecosystem)
PyPI(1)
PackageVulnerable rangeFixed inDependents
praisonai0.0.1 ... 4.5.98 (673 versions)4.5.115—

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 9× in last 7d / 38× 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 104 total refreshes for this CVE.

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

Frequently asked(5)

What is CVE-2026-39890?
CVE-2026-39890 is a critical vulnerability published on April 8, 2026. PraisonAI is a multi-agent teams system. Prior to 4.5.115, the AgentService.loadAgentFromFile method uses the js-yaml library to parse YAML files without disabling dangerous tags (such as !!js/function and !!js/undefined). This allows an attacker to craft a malicious YAML file that, when parsed,…
When was CVE-2026-39890 disclosed?
CVE-2026-39890 was first published in the National Vulnerability Database on April 8, 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-2026-39890 actively exploited?
CVE-2026-39890 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 43.6% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.
What is the CVSS score of CVE-2026-39890?
CVE-2026-39890 has a CVSS v3 base score of 9.8 (NVD).
How do I remediate CVE-2026-39890?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-39890, 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-2026-39890

Explore →

Is Your Infrastructure Affected by CVE-2026-39890?

EchelonGraph automatically scans your cloud infrastructure and maps CVE exposure using blast radius analysis.

Start Free Scan →Browse All CVEs