XSS in Mervinpraison Praisonai
CVE-2026-56840
PraisonAI is a multi-agent teams system. From version 4.5.2 to before version 4.6.59, praisonai.bots.HTTPApproval renders pending tool approval arguments directly into the approval dashboard HTML. An attacker-controlled tool argument can inject JavaScript into that page. When a human opens the approval URL to inspect the risky tool request, the script runs in the dashboard origin and can POST to the same request's /approve/{request_id}/decide endpoint, causing HTTPApproval to return approved=True. This issue has been patched in version 4.6.59.
Vulnerability class: XSS (Cross-Site Scripting)
Published · last modified .
CVSS v3 metric
CVSS v3 base score 8.8 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H.
EPSS exploit prediction
No EPSS score from FIRST.org yet. New CVEs usually get one within a few days; no score means no signal yet, not low risk. How EPSS works.
Affected products
- Mervinpraison Praisonai — versions >= 4.5.2, < 4.6.59
Weakness classification (CWE)
References
Frequently asked questions
- What is CVE-2026-56840?
- CVE-2026-56840 is a high-severity vulnerability in Mervinpraison Praisonai, classified under Cross-site Scripting. CVSS score: 8.8/10. Published 2026-10-23.
- How severe is CVE-2026-56840?
- High severity. CVSS v3 base score is 8.8 out of 10.