CVE-2026-55529 json
PraisonAI: Origin validation bypass in MCP HTTP Stream transport allows browser-mediated unauthenticated tool execution on local MCP server
published 2026-08-25 2 mo ago modified 2026-09-10 1 mo ago also EUVD-2026-65496 , GHSA-wj6g-v78p-6fx3 , PYSEC-2026-3896
- cvss
- 6.9
- 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 7%
- public exploits
- 0
- none known
Summary
PraisonAI is a multi-agent teams system. Prior to praisonai 4.6.58, the MCP HTTP Stream _validate_origin method accepts request_origin.startswith(allowed), so the attacker-controlled localhost.evil.example HTTP origin matches the localhost allowlist. Without an API key, a malicious webpage can submit tools/call requests to the local MCP server and execute exposed tools. This issue is fixed in version 4.6.58.
Patch / fix
- pypi praisonai 4.6.58
- praison praisonai 4.6.58
CISA SSVC
- Exploitation
- Proof of concept is public
- Automatable
- no
- Technical impact
- partial
- Assessed
- 2 mo ago
Exploit prediction
0.18% chance of exploitation in the next 30 days, higher than 7% of all scored CVEs (FIRST EPSS, 2026-11-08).
Exploits and checks
- github.com https://github.com/MervinPraison/PraisonAI/security/advisories/GHSA-wj6g-v78p-6fx3 referenced PoC, tagged "exploit" by a source, unverified
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| CNA | 3.1 | 6.9 | CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:C/C:H/I:L/A:N |
| GitHub | 3.1 | 6.9 | CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:C/C:H/I:L/A:N |
| OSV | 3.1 | 6.9 | CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:C/C:H/I:L/A:N |
Affected packages
| ecosystem | package | affected | fixed in |
|---|---|---|---|
| pypi | praisonai | <4.6.58 |
4.6.58 |
Affected products
- MervinPraison PraisonAI
Classification
References
-
github.com
/MervinPraison/PraisonAI/commit/2f9677abb2ea68eab864ee8b6a828fd0141612e1
web
-
github.com
/MervinPraison/PraisonAI/security/advisories/GHSA-wj6g-v78p-6fx3
exploit, web
-
github.com
/MervinPraison/PraisonAI/releases/tag/v4.6.58
web
-
github.com
/MervinPraison/PraisonAI
package
-
pypi.org
/project/praisonai
package
-
github.com
/advisories/GHSA-wj6g-v78p-6fx3
advisory
-
nvd.nist.gov
/vuln/detail/CVE-2026-55529
advisory
Sources
- CVE List CVE-2026-55529
- GitHub Advisory GHSA-wj6g-v78p-6fx3
- NVD CVE-2026-55529
- OSV PYSEC-2026-3896
Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.
CPEs and fixed versions use Anchore's correction of NVD's data: Added CPE configurations because not yet analyzed by NVD.