PraisonAI MCP HTTP server has unauthenticated unbounded session accumulation (memory exhaustion; session TTL never enforced)

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS

6.5 · CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H

EPSS

• CVE-2026-55531: 0.45% estimated exploitation activity in the next 30 days; percentile 39.31 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.

As published by the source; long descriptions are shortened.

Summary The PraisonAI MCP HTTP-stream server creates a new in-memory session on every initialize request and never removes it. The cleanup routine that would expire sessions (cleanupsessions) is defined but never called anywhere in the codebase, and the configured session TTL is never enforced. There is no cap on the number of sessions. Because initialize requires no authentication and the server keeps every session dictionary forever, an attacker who can reach the endpoint (directly when the server is bound to a routable address, or from a victim's browser via the separate Origin-validation bypass) can drive memory usage up without bound until the process is killed by the out-of-memory killer. The same unbounded-growth pattern also applies to the cancelled-requests set populated by notifications/cancelled. Details In transports/httpstream.py, each initialize creates and stores a session with no limit: A cleanup method exists: but grep across the package shows it has no call sites:…

Published by the source

25 Aug 2026, 14:34 UTC

Last modified by the source

25 Aug 2026, 14:34 UTC

Source last checked

26 Oct 2026, 13:50 UTC

1. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-wv94-5qcp-6m36

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# Patch Next advisory brief: CVE-2026-55531

Advisory: PraisonAI MCP HTTP server has unauthenticated unbounded session accumulation (memory exhaustion; session TTL never enforced)
IDs: CVE-2026-55531, GHSA-wv94-5qcp-6m36
Record: https://patchnext.com/advisories/cve-2026-55531 (revision 1, source checked 26 Oct 2026, 13:50 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: Medium (CVSS 6.5)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: praisonai 4.6.58. A vendor fix does not mean a deployment is fixed.

## Affected components
- PyPI praisonai: affected < 4.6.58; fixed in 4.6.58

## Suggested inspection (read-only)
- `python -m pip show praisonai`: prints the installed version. Run with the environment that serves production active.

## Supported action
Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on praisonai.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://github.com/advisories/GHSA-wv94-5qcp-6m36 (GitHub-reviewed advisory GHSA-wv94-5qcp-6m36 lists affected ranges: PyPI praisonai >=0 <4.6.58)

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