CVE-2026-55531

MEDIUMPre-NVD 6.56.5
EchelonGraph scoreMEDIUM confidence

This medium-severity CVE scores 6.5 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit probability: 0.2%, top 84% 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
6.5EG
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 6.5Exploit: Elevated riskExposed: 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 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
6.5(medium)
EG Risk
45(Track)
EG Risk 45/100SSVC: 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
Severity65% × 45%
Exploitation40% × 40%
Automatability0% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
16%
KEV
Not listed

Published

August 25, 2026

Last Modified

August 25, 2026

Advisory Details (3)

Auto-updated Aug 25, 2026
🔬 Proof of concept available. Patch available. Sources: github, github_commit, github_release.
github Patch Available🟡 PoC Available

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 rangeFixed inDependents
praisonai0.0.1 ... 4.6.9 (748 versions)4.6.58

Weakness Classification(2)

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

Data Freshness Timeline

(refreshed 11× in last 7d / 11× 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. 2026-08-30 01:22 UTCEPSS rescore
  2. 2026-08-29 20:01 UTCEG score recompute
  3. 2026-08-28 21:41 UTCEPSS rescore
  4. 2026-08-27 18:47 UTCEG score recompute
  5. 2026-08-27 14:25 UTCEPSS rescore
  6. 2026-08-26 18:11 UTCEG score recompute
  7. 2026-08-26 14:46 UTCEPSS rescore
  8. 2026-08-25 17:25 UTCEG score recompute
  9. 2026-08-25 16:26 UTCEG score recompute
  10. 2026-08-25 15:21 UTCEG score recompute
  11. 2026-08-25 14:44 UTCEG score recompute

Frequently asked(5)

What is CVE-2026-55531?
CVE-2026-55531 is a medium vulnerability 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 CVE-2026-55531 disclosed?
CVE-2026-55531 was first published in the National Vulnerability Database on August 25, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-55531 actively exploited?
CVE-2026-55531 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0% probability of exploitation in the next 30 days, which ranks it in the top 84.2% of all scored CVEs.
What is the CVSS score of CVE-2026-55531?
CVE-2026-55531 has a CVSS v3 base score of 6.5 (NVD).
How do I remediate CVE-2026-55531?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-55531, 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-2026-55531

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