CVE-2026-40112: CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') in MervinPraison PraisonAI
PraisonAI is a multi-agent teams system. Prior to 4.5.128, the Flask API endpoint in src/praisonai/api.py renders agent output as HTML without effective sanitization. The _sanitize_html function relies on the nh3 library, which is not listed as a required or optional dependency in pyproject.toml. When nh3 is absent (the default installation), the sanitizer is a no-op that returns HTML unchanged. An attacker who can influence agent input (via RAG data poisoning, web scraping results, or prompt injection) can inject arbitrary JavaScript that executes in the browser of anyone viewing the API output. This vulnerability is fixed in 4.5.128.
AI Analysis
Technical Summary
PraisonAI, a multi-agent teams system, contains a cross-site scripting vulnerability (CWE-79) in its Flask API endpoint prior to version 4.5.128. The sanitization function relies on the nh3 library, which is not included by default, resulting in no effective HTML sanitization. Attackers able to manipulate agent input can inject malicious JavaScript that executes in client browsers. This issue is resolved in version 4.5.128.
Potential Impact
An attacker who can influence the input to PraisonAI agents can inject arbitrary JavaScript code that executes in the browsers of users viewing the affected API output. This can lead to client-side code execution, potentially compromising user data or session information. The CVSS score is 5.4 (medium severity), reflecting limited impact due to the requirement for user interaction and attacker control over input.
Mitigation Recommendations
This vulnerability is fixed in PraisonAI version 4.5.128. Users should upgrade to version 4.5.128 or later to remediate the issue. No official patch or remediation level is explicitly stated beyond this version update. Until upgraded, users should ensure the nh3 library is installed to enable effective sanitization or avoid exposing the vulnerable API endpoint to untrusted input.
CVE-2026-40112: CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') in MervinPraison PraisonAI
Description
PraisonAI is a multi-agent teams system. Prior to 4.5.128, the Flask API endpoint in src/praisonai/api.py renders agent output as HTML without effective sanitization. The _sanitize_html function relies on the nh3 library, which is not listed as a required or optional dependency in pyproject.toml. When nh3 is absent (the default installation), the sanitizer is a no-op that returns HTML unchanged. An attacker who can influence agent input (via RAG data poisoning, web scraping results, or prompt injection) can inject arbitrary JavaScript that executes in the browser of anyone viewing the API output. This vulnerability is fixed in 4.5.128.
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
PraisonAI, a multi-agent teams system, contains a cross-site scripting vulnerability (CWE-79) in its Flask API endpoint prior to version 4.5.128. The sanitization function relies on the nh3 library, which is not included by default, resulting in no effective HTML sanitization. Attackers able to manipulate agent input can inject malicious JavaScript that executes in client browsers. This issue is resolved in version 4.5.128.
Potential Impact
An attacker who can influence the input to PraisonAI agents can inject arbitrary JavaScript code that executes in the browsers of users viewing the affected API output. This can lead to client-side code execution, potentially compromising user data or session information. The CVSS score is 5.4 (medium severity), reflecting limited impact due to the requirement for user interaction and attacker control over input.
Mitigation Recommendations
This vulnerability is fixed in PraisonAI version 4.5.128. Users should upgrade to version 4.5.128 or later to remediate the issue. No official patch or remediation level is explicitly stated beyond this version update. Until upgraded, users should ensure the nh3 library is installed to enable effective sanitization or avoid exposing the vulnerable API endpoint to untrusted input.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- GitHub_M
- Date Reserved
- 2026-04-09T01:41:38.536Z
- Cvss Version
- 3.1
- State
- PUBLISHED
- Remediation Level
- null
Threat ID: 69d843751cc7ad14da3fb55f
Added to database: 4/10/2026, 12:25:25 AM
Last enriched: 4/10/2026, 12:51:17 AM
Last updated: 4/10/2026, 8:25:27 AM
Views: 7
Community Reviews
0 reviewsCrowdsource mitigation strategies, share intel context, and vote on the most helpful responses. Sign in to add your voice and help keep defenders ahead.
Want to contribute mitigation steps or threat intel context? Sign in or create an account to join the community discussion.
Actions
Updates to AI analysis require Pro Console access. Upgrade inside Console → Billing.
External Links
Need more coverage?
Upgrade to Pro Console for AI refresh and higher limits.
For incident response and remediation, OffSeq services can help resolve threats faster.
Latest Threats
Check if your credentials are on the dark web
Instant breach scanning across billions of leaked records. Free tier available.