CVE-2026-55529Public exploitNetwork attack vectorHinoki check available

Unauthenticated tool execution via Origin prefix matching

Published Aug 25, 2026 · Updated Aug 27, 2026

Origin validation bypass in PraisonAI before 4.6.58 allows remote attackers to execute exposed tools through a malicious webpage. MCP HTTP Stream's _validate_origin method treats any Origin beginning with an allowlisted localhost value as trusted instead of comparing the complete origin. Exploitation requires a running server without an API key and user interaction with attacker-controlled content; exposed tools can read local files or modify local state.

CVSS severity6.9
Medium
EPSS probability0.12%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkAvailable
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Summary

What happened

Origin validation bypass in PraisonAI before 4.6.58 allows remote attackers to execute exposed tools through a malicious webpage. MCP HTTP Stream's _validate_origin method treats any Origin beginning with an allowlisted localhost value as trusted instead of comparing the complete origin. Exploitation requires a running server without an API key and user interaction with attacker-controlled content; exposed tools can read local files or modify local state.

The record

CVE
CVE-2026-55529
Published
Aug 25, 2026
Updated
Aug 27, 2026
Vendor
PraisonAI
Product
PraisonAI
Classifications
CWE-346, CWE-306, T1189
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Aug 25, 2026CVE publishedPublication date reported by the CVE source.
  2. Aug 27, 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=< 4.6.58

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

PraisonAI · PraisonAIversion=< 4.6.58

Published CVSS scores

6.9GitHubCVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:C/C:H/I:L/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.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-346Origin Validation Error
CWE-306Missing Authentication for Critical Function
T1189Drive-by Compromise

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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