CVE-2026-34953Public exploitNetwork attack vector

Unauthenticated tool access via fail-open token validation

Published Apr 3, 2026 · Updated Apr 3, 2026

Authentication bypass in PraisonAI before 4.5.97 allows remote attackers to access MCP tools with an arbitrary Bearer token. OAuthManager.validate_token() iterates the internal token store but returns True after the loop, so an unknown token is accepted when no match exists. Network access to the HTTP MCP server is sufficient, and the store is empty by default; accepted requests can list and invoke registered tools and agent capabilities.

CVSS severity9.1
Critical
EPSS probability0.38%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Authentication bypass in PraisonAI before 4.5.97 allows remote attackers to access MCP tools with an arbitrary Bearer token. OAuthManager.validate_token() iterates the internal token store but returns True after the loop, so an unknown token is accepted when no match exists. Network access to the HTTP MCP server is sufficient, and the store is empty by default; accepted requests can list and invoke registered tools and agent capabilities.

The record

CVE
CVE-2026-34953
Published
Apr 3, 2026
Updated
Apr 3, 2026
Vendor
Mervin Praison
Product
PraisonAI
Classifications
CWE-863, T1190
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Apr 3, 2026CVE publishedPublication date reported by the CVE source.
  2. Apr 3, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=< 4.5.97

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Mervin Praison · PraisonAIversion=< 4.5.97

Published CVSS scores

9.1GitHub, Inc.CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-863Incorrect Authorization
T1190Exploit Public-Facing Application

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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