CVE-2026-86242 — Bifrost HTTP transport before 2.0.0 accepts an enabled custom plugin whose path is an…¶
Key facts
CVE-2026-86242 is a High (8.1) vulnerability: Bifrost HTTP transport before 2.0.0 accepts an enabled custom plugin whose path is an…. This entry ships a detection-only PoC and a Docker test lab.
| CVE | CVE-2026-86242 |
| Severity | High (8.1) |
| Detection / prevention | — |
| PoC | poc.py |
| Source | 2026/CVE-2026-86242/ |
Details¶
English | 한국어
Description¶
Bifrost HTTP transport before 2.0.0 accepts an enabled custom plugin whose path is an HTTP URL through unauthenticated POST /api/plugins when management authentication is disabled (the default, governance.auth_config.is_enabled=false). The shared-object loader treats an http-prefixed path as a download URL, writes the body to a temporary .so, and passes it to Go's plugin.Open. After a successful open, optional Init runs immediately with the supplied config as the Bifrost process user. On documented dynamically linked builds (DYNAMIC=1 / no static-link flags), which the vendor requires for custom Go plugins, plugin.Open is expected to succeed and this is unauthenticated remote code execution. On the published statically linked Docker image, plugin.Open fails with Dynamic loading not supported, so that build class is only server-side request forgery. Attack complexity is High because the attacker cannot force RCE on the default static image and a loadable plugin must match the host Go version, OS, architecture, and linkage. The 1.6.x HTTP transport line through 1.6.11 does not contain the fix.
Vulnerability Details¶
| Property | Value |
|---|---|
| CVE ID | CVE-2026-86242 |
| Type | SSRF |
| CVSS Score | 8.1 |
Proof of Concept¶
Download¶
# Download PoC script
curl -O https://raw.githubusercontent.com/fankh/vulnerability-poc/main/2026/CVE-2026-86242/poc.py
Usage¶
# Run PoC against target
python3 poc.py --target <TARGET_URL>
# With authentication
python3 poc.py --target <TARGET_URL> --username <USER> --password <PASS>
⚠️ Warning: This PoC is for authorized security testing only. It uses detection-only techniques and does not exploit or damage target systems.
Test Lab¶
This repository includes a Docker-based test environment with both vulnerable and patched applications.
Quick Start¶
# Clone and navigate to CVE directory
cd CVE-2026-86242
# Start both applications
docker-compose up -d
# Run tests
./run-tests.sh # Linux/Mac
./run-tests.ps1 # Windows PowerShell
Application Endpoints¶
| Application | URL | Status |
|---|---|---|
| Vulnerable App | http://localhost:8080 | Shows vulnerability |
| Patched App | http://localhost:8081 | Demonstrates fix |
Directory Structure¶
├── README.md # English documentation
├── README_KO.md # Korean documentation
├── poc.py # PoC detection script
├── docker-compose.yml # Container orchestration
├── run-tests.sh # Linux/Mac test runner
├── run-tests.ps1 # Windows test runner
├── vulnerable-app/ # Vulnerable version
│ ├── app.py
│ ├── Dockerfile
│ └── requirements.txt
└── patched-app/ # Fixed version
├── app.py
├── Dockerfile
└── requirements.txt
References¶
- https://github.com/maximhq/bifrost
- https://github.com/maximhq/bifrost/commit/e0057ff355f831c251eabe9d0e44f3a3748532c6
- https://github.com/maximhq/bifrost/pull/5763
- https://github.com/maximhq/bifrost/releases/tag/transports/v2.0.0
- https://github.com/maximhq/bifrost/security/advisories/GHSA-2qp8-4xgm-fw6g
Generated by PoC Generator on 2026-09-07T03:46:09.646146807
Frequently asked questions¶
What is CVE-2026-86242?¶
CVE-2026-86242 is a High (8.1) vulnerability: Bifrost HTTP transport before 2.0.0 accepts an enabled custom plugin whose path is an…. This entry ships a detection-only PoC and a Docker test lab.
How do I detect CVE-2026-86242?¶
Run the detection-only PoC included with this entry against your Docker test lab to confirm whether a target is affected; pair it with your own IDS logging.
How do I block or mitigate CVE-2026-86242?¶
Upgrade to a fixed version per the vendor advisory; the NVD record lists the affected versions. Use the included PoC to verify your remediation.
For authorized security testing and research only. See the full source and NVD record.