CVE-2026-55531

MEDIUMPre-NVD 6.56.5
EchelonGraph scoreMEDIUM confidence

“—” beside the score: it is equal to the CVSS score beside it.

This medium-severity CVE scores 6.5 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit probability: 0.5% (37th percentile of EPSS-scored CVEs). No GitHub Security Advisory CVSS is on record for this CVE.

Triggered by: Headline CVSS from a secondary CVSS source
Sources: EPSS, a secondary CVSS source
Elevated
6.5EG
EchelonGraph verdictPlan a fixRemediate within your standard update timelines (the SSVC decision on this page).
  • CISA's Vulnrichment rates exploitation as PoC; EchelonGraph holds no exploit-code reference for it
CISA-KEV: Not listedEPSS PROB: 0.5%CVSS: 6.5Exploit: No code on recordExposed services: Not assessed

A fix is available — apply it.

PraisonAI is a multi-agent teams system. Prior to praisonai 4.6.58, the MCP HTTP Stream mcp_post handler creates a new _sessions entry for every initialize request but does not call _cleanup_sessions or enforce a maximum. An unauthenticated caller can exhaust memory. The fix invokes cleanup and limits sessions through PRAISONAI_MCP_MAX_SESSIONS. This issue is fixed in version 4.6.58.

CVSS v3
6.5
EG Score
6.5MEDIUMmedium confidence
EG Risk
45
EG Risk 45/100

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 (value × EchelonGraph’s weight)
Severity65% × 45%
The EG Score, 6.5 of 10.
Exploitation40% × 40%
EchelonGraph's fixed weight for EG-KEV Tier 3 (Elevated): a constant, not a probability.
Automatability0% × 15%
CISA's SSVC Automatable value: no (Vulnrichment).
SSVC (CISA's decision table, applied by EchelonGraph): Track at low or medium mission impact; Track* at high (mission-essential systems).
Exploitation public PoC (CISA Vulnrichment) · Automatable no (CISA Vulnrichment) · Technical impact partial (CISA Vulnrichment). All three are CISA's SSVC values (Vulnrichment). EchelonGraph applied CISA's decision table to them; CISA publishes SSVC inputs and the table, not a decision for each CVE.
Action: A fix is available. Apply it within your standard update timelines.
EPSS PROB
0.5%
EPSS %ILE
37th
KEV
Not listed

SSVC (CISA's decision table, applied by EchelonGraph)Track at low or medium mission impact; Track* at high (mission-essential systems).

A fix is available. Apply it within your standard update timelines.

Exploitation public PoC (CISA Vulnrichment) · Automatable no (CISA Vulnrichment) · Technical impact partial (CISA Vulnrichment). All three are CISA's SSVC values (Vulnrichment). EchelonGraph applied CISA's decision table to them; CISA publishes SSVC inputs and the table, not a decision for each CVE. Mission impact is CISA's Mission & Well-being decision point, and only you can judge it. CISA's table makes it high when Mission Prevalence is Essential — the vulnerable component "directly provides capabilities that constitute at least one MEF for at least one entity" (MEF: mission essential function) — or when Public Well-Being Impact is Irreversible: "multiple fatalities are likely", the cyber-physical system "is likely lost or destroyed", "extreme or serious externalities" are imposed on other parties, or social systems such as elections or the financial grid "are destabilized and potentially collapse". CISA's decision table

BOD 26-04 (CISA's remediation timeline, Table 1)60 days if the affected system is publicly exposed; Fix on system upgrade if it is not.

In CISA KEV no (CISA's KEV catalog) · Automatable no (CISA Vulnrichment) · Technical impact partial (CISA Vulnrichment). Whether your system is publicly exposed is yours to answer. BOD 26-04 binds US Federal Civilian Executive Branch agencies; for anyone else it is CISA's published timeline, a reference rather than an obligation. The directive · how EchelonGraph applies it

Published

August 25, 2026

Last Modified

September 9, 2026

Advisory Details (3)

Auto-updated Aug 25, 2026
Patch available. Sources: github, github_commit, github_release.
GitHub advisoryMentions a patch (unverified)

Unauthenticated unbounded session accumulation in the PraisonAI MCP HTTP server (memory exhaustion; session TTL never enforced) · Advisory · MervinPraison/PraisonAI · GitHub

https://github.com/MervinPraison/PraisonAI/security/advisories/GHSA-wv94-5qcp-6m36
GitHub release Patch Available

PraisonAI v4.6.58

Patch available: MervinPraison/PraisonAI v4.6.58

https://github.com/MervinPraison/PraisonAI/releases/tag/v4.6.58
GitHub commit Patch Available

commit 2f9677abb2ea (MervinPraison/PraisonAI)

Patch available: MervinPraison/PraisonAI v4.6.137 (contains commit 2f9677abb2ea)

https://github.com/MervinPraison/PraisonAI/commit/2f9677abb2ea68eab864ee8b6a828fd0141612e1

Vendor Advisories for CVE-2026-55531(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)
PyPI(1)
PackageVulnerable rangeFix by version rangeDependents
praisonai0.0.1 ... 4.6.9 (748 versions)
  • every version up to 4.6.58: fixed in 4.6.58
—

Weakness Classification(2)

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

Data Freshness Timeline

(refreshed 14× in last 7d / 52× in last 30d)

Each row is a time one of our pipelines fetched, updated or re-scored this CVE. 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. An arrow marks a change the record states ("CVSS v3 → 9.1"); EPSS and GHSA rows show the values recorded at that time, not what changed (EPSS values are rounded; hover one for the exact figures). Most recent first.

  1. 2026-10-13 16:34 UTCEPSS rescoreEPSS 0.5% · 37th percentile
  2. 2026-10-12 16:34 UTCEPSS rescoreEPSS 0.5% · 37th percentile
  3. 2026-10-12 15:55 UTCEG score recompute
  4. 2026-10-11 19:39 UTCEG score recompute
  5. 2026-10-11 16:54 UTCEG score recompute
  6. 2026-10-11 14:17 UTCEG score recompute
  7. 2026-10-11 13:49 UTCEPSS rescoreEPSS 0.5% · 37th percentile
  8. 2026-10-10 20:00 UTCEPSS rescoreEPSS 0.5% · 37th percentile
  9. 2026-10-10 12:05 UTCEG score recompute
  10. 2026-10-09 20:07 UTCEPSS rescoreEPSS 0.5% · 37th percentile
  11. 2026-10-09 04:24 UTCEG score recompute
  12. 2026-10-08 17:12 UTCEPSS rescoreEPSS 0.5% · 37th percentile
  13. 2026-10-08 03:18 UTCEG score recompute
  14. 2026-10-07 23:48 UTCEPSS rescoreEPSS 0.5% · 37th percentile
  15. 2026-10-06 21:14 UTCEG score recompute
  16. 2026-10-06 15:18 UTCEPSS rescoreEPSS 0.5% · 37th percentile
  17. 2026-10-05 20:32 UTCEG score recompute
  18. 2026-10-05 17:43 UTCEPSS rescoreEPSS 0.5% · 37th percentile
  19. 2026-10-04 23:22 UTCEPSS rescoreEPSS 0.5% · 37th percentile
  20. 2026-10-03 16:26 UTCEG score recompute
  21. 2026-10-03 14:26 UTCEPSS rescoreEPSS 0.5% · 37th percentile
  22. 2026-10-02 17:56 UTCEPSS rescoreEPSS 0.5% · 37th percentile
  23. 2026-10-02 07:59 UTCEG score recompute
  24. 2026-10-01 19:50 UTCEPSS rescoreEPSS 0.5% · 36th percentile
  25. 2026-10-01 07:23 UTCEG score recompute
Show 61 more
  1. 2026-09-30 15:03 UTCEPSS rescoreEPSS 0.5% · 36th percentile
  2. 2026-09-30 06:49 UTCEG score recompute
  3. 2026-09-29 15:22 UTCEPSS rescoreEPSS 0.5% · 36th percentile
  4. 2026-09-28 23:22 UTCEG score recompute
  5. 2026-09-28 13:51 UTCEPSS rescoreEPSS 0.5% · 36th percentile
  6. 2026-09-27 22:40 UTCEG score recompute
  7. 2026-09-27 13:48 UTCEPSS rescoreEPSS 0.5% · 36th percentile
  8. 2026-09-26 22:06 UTCEG score recompute
  9. 2026-09-26 15:59 UTCEPSS rescoreEPSS 0.5% · 36th percentile
  10. 2026-09-25 07:54 UTCEG score recompute
  11. 2026-09-24 14:04 UTCEPSS rescoreEPSS 0.5% · 36th percentile
  12. 2026-09-24 07:20 UTCEG score recompute
  13. 2026-09-23 17:54 UTCEPSS rescoreEPSS 0.2% · 16th percentile
  14. 2026-09-23 06:45 UTCEG score recompute
  15. 2026-09-22 06:11 UTCEG score recompute
  16. 2026-09-21 05:37 UTCEG score recompute
  17. 2026-09-20 20:16 UTCEPSS rescoreEPSS 0.2% · 16th percentile
  18. 2026-09-20 03:58 UTCEG score recompute
  19. 2026-09-19 03:23 UTCEG score recompute
  20. 2026-09-18 19:28 UTCEPSS rescoreEPSS 0.2% · 16th percentile
  21. 2026-09-18 02:49 UTCEG score recompute
  22. 2026-09-17 19:31 UTCEPSS rescoreEPSS 0.2% · 16th percentile
  23. 2026-09-17 02:15 UTCEG score recompute
  24. 2026-09-16 14:08 UTCEPSS rescoreEPSS 0.2% · 16th percentile
  25. 2026-09-16 05:15 UTCEPSS rescoreEPSS 0.2% · 16th percentile
  26. 2026-09-16 01:41 UTCEG score recompute
  27. 2026-09-15 03:11 UTCEPSS rescoreEPSS 0.2% · 16th percentile
  28. 2026-09-14 00:32 UTCEG score recompute
  29. 2026-09-13 16:47 UTCEPSS rescoreEPSS 0.2% · 16th percentile
  30. 2026-09-12 23:58 UTCEG score recompute
  31. 2026-09-11 23:23 UTCEG score recompute
  32. 2026-09-11 14:53 UTCEPSS rescoreEPSS 0.2% · 15th percentile
  33. 2026-09-10 21:52 UTCEG score recompute
  34. 2026-09-10 09:35 UTCEPSS rescoreEPSS 0.2% · 15th percentile
  35. 2026-09-09 02:04 UTCEG score recompute
  36. 2026-09-08 22:01 UTCEPSS rescoreEPSS 0.2% · 15th percentile
  37. 2026-09-08 01:30 UTCEG score recompute
  38. 2026-09-07 16:01 UTCEPSS rescoreEPSS 0.2% · 15th percentile
  39. 2026-09-07 00:55 UTCEG score recompute
  40. 2026-09-06 13:47 UTCEPSS rescoreEPSS 0.2% · 15th percentile
  41. 2026-09-06 00:15 UTCEG score recompute
  42. 2026-09-04 23:41 UTCEG score recompute
  43. 2026-09-04 05:06 UTCEPSS rescoreEPSS 0.2% · 15th percentile
  44. 2026-09-02 22:21 UTCEG score recompute
  45. 2026-09-02 14:12 UTCEPSS rescoreEPSS 0.2% · 15th percentile
  46. 2026-09-01 21:45 UTCEG score recompute
  47. 2026-09-01 13:54 UTCEPSS rescoreEPSS 0.2% · 15th percentile
  48. 2026-09-01 04:40 UTCEPSS rescoreEPSS 0.2% · 15th percentile
  49. 2026-08-30 20:35 UTCEG score recompute
  50. 2026-08-30 19:17 UTCEPSS rescoreEPSS 0.2% · 15th percentile
  51. 2026-08-30 01:22 UTCEPSS rescoreEPSS 0.2% · 15th percentile
  52. 2026-08-29 20:01 UTCEG score recompute
  53. 2026-08-28 21:41 UTCEPSS rescoreEPSS 0.2% · 15th percentile
  54. 2026-08-27 18:47 UTCEG score recompute
  55. 2026-08-27 14:25 UTCEPSS rescoreEPSS 0.2% · 15th percentile
  56. 2026-08-26 18:11 UTCEG score recompute
  57. 2026-08-26 14:46 UTCEPSS rescoreEPSS 0.2% · 15th percentile
  58. 2026-08-25 17:25 UTCEG score recompute
  59. 2026-08-25 16:26 UTCEG score recompute
  60. 2026-08-25 15:21 UTCEG score recompute
  61. 2026-08-25 14:44 UTCEG score recomputeFirst assessed: 6.5 MEDIUM

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Frequently asked(5)

What is CVE-2026-55531?
CVE-2026-55531 is a medium-severity vulnerability; its CVE record was published on August 25, 2026. PraisonAI is a multi-agent teams system. Prior to praisonai 4.6.58, the MCP HTTP Stream mcppost handler creates a new sessions entry for every initialize request but does not call cleanupsessions or enforce a maximum. An unauthenticated caller can exhaust memory. The fix invokes cleanup and limits…
When was the CVE record for CVE-2026-55531 published?
The CVE record for CVE-2026-55531 was published on August 25, 2026. That is the record's publication date; the vulnerability itself may have been made public earlier. EchelonGraph's copy of the record carries a last-modified date of September 9, 2026; the record at its source may have been updated since.
Is CVE-2026-55531 actively exploited?
CVE-2026-55531 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.5% probability of exploitation in the next 30 days (37th percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-55531?
CVE-2026-55531 has a CVSS base score of 6.5 (a secondary CVSS source that NVD displays; NVD's own analysis pending).
How do I remediate CVE-2026-55531?
A fix for CVE-2026-55531 is available: update to the fixed version the vendor names in its advisory. The vendor advisories EchelonGraph has for CVE-2026-55531 are linked in the Vendor Advisories panel on this page.

Dependency Blast Radius

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