TI-2026-28938 Aliases CVE-2026-40112 GHSA-cfg2-mxfj-j6pw

PraisonAI has Stored XSS via Unsanitized Agent Output in HTML Rendering (nh3 Not a Required Dependency)

MEDIUM 60CWE-79Published 2026-04-09 · Updated 2026-04-14

Key facts

Attack vector: Network
Privileges required: None
User interaction: Required
Attack complexity: Low
Impact type: Cross-site scripting
Confidentiality · integrity · availability: Low · Low · None
Fix status: Fixed

Attack profile from CVSS 3.1 · NVD. Fix status from CNA and GitHub. Impact type from CWE-79.

Summary

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.

Why it matters now

Exploitation Proof of concept CISA SSVC · not in CISA KEV

EPSS 0.00224 13th percentileScored 2026-11-07

Public exploit Yes 1 exploit referenceTagged by NVD

Fix Fixed PraisonAI (MervinPraison): 4.5.128PraisonAI (PyPI): 4.5.128

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation: Poc
Automatable: No
Technical impact: Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

Vendor	Product	Affected versions	Fixed in	Status	Source
MervinPraison	PraisonAI	before 4.5.128	4.5.128	Patch available	CNA
—	PraisonAI (PyPI)	before 4.5.128	4.5.128	Patch available	GHSA-cfg2-mxfj-j6pw

PraisonAI VendorMervinPraison Affected before 4.5.128 Fixed in 4.5.128 Patch available CNA
PraisonAI (PyPI) Vendor— Affected before 4.5.128 Fixed in 4.5.128 Patch available GHSA-cfg2-mxfj-j6pw

CPE configurations NVD · 1

CPE	Versions	Role	Vendor
cpe:2.3:a:praison:praisonai::::::::	before 4.5.128	Vulnerable	MervinPraison

cpe:2.3:a:praison:praisonai:*:*:*:*:*:*:*:* Versions before 4.5.128 Vulnerable ·MervinPraison

Remediation

Fix · CNA PraisonAI (MervinPraison) Fixed in 4.5.128
Fix · GHSA-cfg2-mxfj-j6pw PraisonAI (PyPI) Fixed in 4.5.128 Advisory →

Timeline

2026-10-02 Threatist record created from CVE-2026-40112
2026-10-03 Alias added: GHSA-cfg2-mxfj-j6pw

References

Exploit 1

https://github.com/MervinPraison/PraisonAI/security/advisories/GHSA-cfg2-mxfj-j6pw

Advisory 1

https://nvd.nist.gov/vuln/detail/CVE-2026-40112

Other 2

TI-2026-30083 Incomplete fix for CVE-2026-34935: Command Injection in MervinPraison/PraisonAI CVSS 3.1CRITICAL 9.8
TI-2026-29070 PraisonAI: Critical RCE via `type: job` workflow YAML CVSS 3.1CRITICAL 9.8
TI-2026-28940 PraisonAI has Server-Side Request Forgery via Unvalidated webhook_url in Jobs API CVSS 3.1CRITICAL 10.0
TI-2026-28768 PraisonAI Affected by Remote Code Execution via YAML Deserialization in Agent Definition Loading CVSS 3.1CRITICAL 9.8
TI-2026-27159 PraisonAI: OS Command Injection in MCPHandler.parse_mcp_command() CVSS 3.1CRITICAL 9.8
TI-2026-27158 PraisonAI: Second-Order SQL Injection in `get_all_user_threads` CVSS 3.1CRITICAL 9.8

See all 42 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences