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CVE-2026-61439: Prompt Injection Defense Bypass in PraisonAI InjectionDefense Engine
Vulnerability ID: CVE-2026-61439 CVSS Score: 7.5
Published: 2026-10-07 This report provides a comprehensive technical analysis of CVE-2026-61439 (GHSA-fj8f-m44g-c479), a prompt injection defense bypass vulnerability in the PraisonAI multi-agent framework. In versions prior to 4.6.78, the InjectionDefense scanner threshold defaulted to CRITICAL. This allowed single-vector prompt injections classified as HIGH severity (e.g., direct instruction overrides or financial manipulations) to pass through unblocked, enabling attackers to extract system prompts and execute unauthorized agent tools.
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TL;DR
PraisonAI versions before 4.6.78 contain an insecure default configuration in the InjectionDefense component, allowing high-severity prompt injections to bypass active blocking controls.
⚠️ Exploit Status: POC
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Technical Details
CWE ID : CWE-1188 #
Attack Vector : Network (AV:N) #
CVSS v3.1 Score : 7.5 (High) #
EPSS Score / Percentile : 0.00432 (0.43% probability) / 35.46th percentile #
Impact : Confidentiality Breach / System Prompt Extraction #
Exploit Status : Proof-of-Concept / Logical Bypass #
CISA KEV Status : Not Listed
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Affected Systems
- PraisonAI Framework
- PraisonAI Agents Module
PraisonAI : < 4.6.78 (Fixed in:4.6.78 )
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Code Analysis
Fix default block threshold in prompt injection defense to HIGH severity
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Mitigation Strategies
- Upgrade to PraisonAI version 4.6.78 or newer to apply the secure-by-default behavior.
- Manually configure the block_threshold parameter to ThreatLevel.HIGH when instantiating the InjectionDefense class.
- Implement real-time monitoring and alerting for ThreatLevel.HIGH logs that bypass active blocking in legacy installations.
Remediation Steps:
- Identify all microservices and deployments utilizing PraisonAI or praisonaiagents.
- Execute pip install --upgrade praisonai praisonaiagents to update the dependency to version 4.6.78 or higher.
- If immediate upgrading is impossible, edit application initialization code to enforce block_threshold=ThreatLevel.HIGH.
- Verify the configuration by executing a test query containing a single-vector prompt override and confirming it is blocked.
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References
Read the full report for CVE-2026-61439 on our website for more details including interactive diagrams and full exploit analysis.