# CVE-2026-39889: PraisonAI has Unauthenticated SSE Event Stream Exposes All Agent Activity in A2U Server

> Unauthenticated access to A2U event streams allows attackers to view all agent activity in PraisonAI.

- **Severity:** High 7.5 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 8 Apr 2026
- **Updated:** 10 Apr 2026
- **Also known as:** GHSA-f292-66h9-fpmf, PYSEC-2026-2911

## What is CVE-2026-39889?

CVE-2026-39889 is a high-severity vulnerability in MervinPraison PraisonAI, published on 8 Apr 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

PraisonAI is a multi-agent teams system. Prior to 4.5.115, the A2U (Agent-to-User) event stream server in PraisonAI exposes all agent activity without authentication. The create_a2u_routes() function registers the following endpoints with NO authentication checks: /a2u/info, /a2u/subscribe, /a2u/events/{stream_name}, /a2u/events/sub/{id}, and /a2u/health. This vulnerability is fixed in 4.5.115.

Weakness: CWE-200 (Exposure of Sensitive Information to an Unauthorized Actor)

## Which versions are affected by CVE-2026-39889?

3 open source packages ship an affected version, including praisonai. It affects 1 product.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `praisonai` | PyPI | All versions | 4.5.115 |
| `praisonai` | PyPI | All versions | 4.5.115 |
| `praisonai` | PyPI | All versions | 4.5.115 |

Products: Praison Praisonai.

## How do I fix CVE-2026-39889?

Upgrade praisonai to 4.5.115 or later.

## Is CVE-2026-39889 being exploited?

There is no known exploitation of CVE-2026-39889 in the wild and no public exploit code.

## Other vulnerabilities in MervinPraison PraisonAI

- [CVE-2026-39888](https://insights.sbomify.com/CVE-2026-39888/): PraisonAIAgents has a sandbox escape via exception frame traversal in `execute_code` (subprocess mode) (critical 10.0)
- [CVE-2026-41497](https://insights.sbomify.com/CVE-2026-41497/): Incomplete fix for CVE-2026-34935: Command Injection in MervinPraison/PraisonAI (critical 9.8)
- [CVE-2026-40288](https://insights.sbomify.com/CVE-2026-40288/): PraisonAI: Critical RCE via `type: job` workflow YAML (critical 9.8)
- [CVE-2026-39890](https://insights.sbomify.com/CVE-2026-39890/): PraisonAI Affected by Remote Code Execution via YAML Deserialization in Agent Definition Loading (critical 9.8)
- [CVE-2026-34934](https://insights.sbomify.com/CVE-2026-34934/): PraisonAI: Second-Order SQL Injection in `get_all_user_threads` (critical 9.8)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-39889 and fix it if it is affected.

What it is: CVE-2026-39889 is a high-severity vulnerability in MervinPraison PraisonAI, published on 8 Apr 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-39889 in the wild and no public exploit code.

Affected packages and fixed versions:
- praisonai (PyPI): affected all versions; fixed in 4.5.115
- praisonai (PyPI): affected all versions; fixed in 4.5.115
- praisonai (PyPI): affected all versions; fixed in 4.5.115

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-39889/ (Markdown: https://insights.sbomify.com/CVE-2026-39889/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-39889
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-39889
- OSV: https://osv.dev/vulnerability/CVE-2026-39889

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-39889/
Summaries are generated and may contain mistakes; the official description above is the record.