CVE-2026-33057
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.
Published Updated Sources: NVD, mesop-dev (CNA), SOCRadar CTI
Triage
Is it exploited, how likely is exploitation, what does it touch, and how severe do the scoring sources call it.
Exploitation
Exploit code
public exploit, none observed
EPSS
5%
ahead of 92% of scored CVEs
CVSS base
9.8
critical
CISA SSVC assessment
Three decision points CISA publishes for the CVEs it assesses · SSVC 2.0.3. A stakeholder decision, not a severity score.
Exploitation
PoC
none · proof-of-concept · active
Automatable
Yes
can an attacker script all four kill-chain steps
Technical impact
Total
partial · total control of the vulnerable component
Remediation
The vendor's own words where we have them.
Upgrade mesop to a fixed release. Apply vendor patches per advisory and restrict external exposure of the affected component until patched.
First 24 hours
Ordered from the record's own fields — exposure first, because you cannot patch what you have not found.
- Identify exposed assets running affected vendor/product/version combinations.
- Prioritize based on EPSS, PoC availability, and external exposure.
- Search available logs for exploit probes, errors, authentication anomalies, or suspicious child processes matching the vulnerability class.
Affected scope
Vendor, product and version as the advisories word them.
| Vendor | Product | Versions | Status |
|---|---|---|---|
| mesop-dev | mesop | < 1.2.3 | Vulnerable |
Attack characteristics
The CVSS vector, decoded. It describes the attack, not your exposure to it.
Availability
High
Confidentiality
High
Integrity
High
Scope
Unchanged
Attack Complexity
Low
Attack Vector
Network
Privileges Req
None
User Interaction
None
Every base score collected
Sources score independently and disagree; each row says who scored it and under which version.
| Score | Version | Severity | Expl. | Impact | Source |
|---|---|---|---|---|---|
| 9.8 | CVSS 3.1 | critical | 3.9 | 5.9 | GitHub (CNA), mesop-dev (CNA) |
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
What this weakness leads to
MITRE's own consequences and mitigations for the weakness class — the authority's wording, not guidance derived from the CVSS vector.
CWE-94 · Improper Control of Generation of Code ('Code Injection')
- Bypass Protection Mechanism
- Gain Privileges or Assume Identity
- Execute Unauthorized Code or Commands
- Hide Activities
Mitigation: Refactor your program so that you do not have to dynamically generate code.
Weakness & attack patterns
- CWE-94Code Injection
Attack patterns reported against this CVE. The ATT&CK techniques below are inferred from its weakness class.
- T1027.006Obfuscated Files or Information: HTML Smuggling
- T1027.009Obfuscated Files or Information: Embedded Payloads
- T1564.009Hide Artifacts: Resource Forking
Public exploit
Capability, not use: code existing is a different claim from anyone running it.
Exploit entries
1
Exploit-DB and CTI exploit indexes
Social mentions
Posts naming this CVE. Attention, not evidence of exploitation — it spikes on disclosure and decays whether or not anything is exploited.
🔴 CVE-2026-33057 - Critical 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 direct... https://t.co/81o7HJZLiY https://t.co/J5c407V9K4
@TheHackerWire· Mar 20, 2026
Unauthenticated Remote Code Execution (CVE-2026-33057) impacts `Mesop` via its `/exec-py` route. Admins should identify affected systems and apply network restrictions. #RCE #Python #InfoSec https://t.co/SaqhBslRTv
@pulsepatchio· Mar 20, 2026
[CVE-2026-33057: CRITICAL] Python-based UI framework Mesop versions 1.2.2 & below have a critical security flaw allowing unrestricted remote code execution via unauthenticated endpoints, fixed in 1.2.3.#cve,CVE-2026-33057,#cybersecurity https://t.co/dKZyNdM5xE
@CveFindCom· Mar 20, 2026
Detection
Read off the CVSS vector and the weakness class. Starting points, not rules we have tested.
- Search application, proxy, and WAF logs for requests touching /sandbox/wsgi_app.py, /exec-py.
- Prioritize edge telemetry for network-reachable mesop.
- Monitor for scanner or exploit-pattern traffic after 1 public PoC repositories were reported.
Timeline
What happened to this CVE, newest first — with the readings a source repeats on a schedule counted underneath rather than listed.
- 2026
Added · CVSS 3.1 9.8 (AV:N)
Jun 17, 2026 · NVD
Initial · CVE published
Mar 20, 2026 · NVD
Source activity
Readings a source repeats on a schedule, counted rather than listed.
- 1×CVE modified by MITRE: CVSS metrics updated.Mar 24, 2026 · SOCRadar CTI
- 1×Tweets · 3 times tweeted.Mar 21, 2026 · SOCRadar CTI
- 1×1 time mentioned on 1 Telegram channelMar 20, 2026 · SOCRadar CTI
References
2 on the record
- github.com/mesop-dev/mesop/commit/825f55970c20686de3f28e2c66df4d74e9d4db47
Patch, Mitre, NIST
- github.com/mesop-dev/mesop/security/advisories/GHSA-gjgx-rvqr-6w6v
Vendor Advisory, Mitre, NIST
Coverage
1 story from the feeds we poll
Elsewhere on this site
- mesop-devevery CVE for this vendor
- Remote Code Execsame class
- CWE-94other pages naming this weakness
Not in any source we poll
Listed rather than left blank: an empty field and an unmeasured one look identical on screen, and only one is a reason to look elsewhere.
- No confirmed IOCs, IP addresses, domains, file hashes, or malware artifacts supplied.
- No organization-specific asset inventory, compensating-control status, or patch deployment evidence supplied.
- No exploit packet captures, log samples, or incident case IDs supplied.
Answered from this record1
What should defenders know first?
CVE-2026-33057 is Mesop Affected by Unauthenticated Remote Code Execution via Test Suite Route /exec-py, a critical vulnerability affecting mesop from mesop-dev. The current evidence does not list it in CISA KEV, and the exploit status is: Active exploitation is not confirmed from current sources for CVE-2026-33057. Public exploit evidence is: 1 public PoC repositories reported; 0 marked weaponized in current dataset. The affected-version evidence is listed in the key facts and affected products tables. Defenders should first verify whether exposed or business-critical assets run those versions, then apply vendor patches or mitigations, restrict reachable attack surface, and preserve logs for detection review. CVSS 9.8 describes technical severity, while EPSS 5% helps estimate near-term exploit likelihood; neither replaces asset context. Unknown fields should remain explicit in tickets, and threat actor, IOC, victimology, or payload claims should not be added unless a cited source supports them. Monitor CISA KEV, vendor advisories, NVD changes, public PoC repositories, and internal telemetry for update triggers.
