CVE-2026-40112 json
PraisonAI has Stored XSS via Unsanitized Agent Output in HTML Rendering (nh3 Not a Required Dependency)
published 2026-04-09 7 mo ago modified 2026-10-26 13 d ago also GHSA-cfg2-mxfj-j6pw , PYSEC-2026-2910 , EUVD-2026-21154
- cvss
- 5.4
- version 3.1, CNA
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 0.2%
- EPSS 0.2% chance of exploitation in 30 days, percentile 13%
- public exploits
- 0
- none known
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.
Patch / fix
- pypi praisonai 4.5.128
- praison praisonai 4.5.128
CISA SSVC
- Exploitation
- Proof of concept is public
- Automatable
- no
- Technical impact
- partial
- Assessed
- 6 mo ago
Exploit prediction
0.22% chance of exploitation in the next 30 days, higher than 13% of all scored CVEs (FIRST EPSS, 2026-11-08).
Exploits and checks
- github.com https://github.com/MervinPraison/PraisonAI/security/advisories/GHSA-cfg2-mxfj-j6pw referenced PoC, tagged "exploit" by a source, unverified
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| CNA | 3.1 | 5.4 | CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:N |
| NVD | 3.1 | 6.1 | CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N |
| GitHub | 3.1 | 5.4 | CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:N |
| OSV | 3.1 | 5.4 | CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:N |
Affected packages
| ecosystem | package | affected | fixed in |
|---|---|---|---|
| pypi | praisonai | <4.5.128 |
4.5.128 |
Affected products
- MervinPraison PraisonAI
Classification
- Weakness
-
- CWE-79 Improper Neutralization of Input During Web Page Generation
References
-
github.com
/MervinPraison/PraisonAI/security/advisories/GHSA-cfg2-mxfj-j6pw
exploit, web, vendor-advisory
-
nvd.nist.gov
/vuln/detail/CVE-2026-40112
advisory
-
github.com
/MervinPraison/PraisonAI
package
-
github.com
/MervinPraison/PraisonAI/releases/tag/v4.5.128
web
-
pypi.org
/project/praisonai
package
-
github.com
/advisories/GHSA-cfg2-mxfj-j6pw
advisory
Sources
- CVE List CVE-2026-40112
- GitHub Advisory GHSA-cfg2-mxfj-j6pw
- NVD CVE-2026-40112
- OSV PYSEC-2026-2910
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