CVE-2026-33054

Name: CVE-2026-33054
Creator: NVD / NIST
Published: 2026-03-20T07:16:13.363+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

CRITICALCVSS 9.8/10EPSS 0.71%

Last modified Jun 17, 2026

CVE-2026-33054 is a critical-severity vulnerability rated 9.8/10 on the CVSS scale. Mesop is a Python-based UI framework that allows users to build web applications. Versions 1.2.2 and below contain a Path Traversal vulnerability that allows any user supplying an untrusted state_token through the UI stream payload to arbitrarily target files on the disk under the standard file-based runtime backend. EPSS estimates a 0.71% chance of exploitation in the next 30 days.

Description

Mesop is a Python-based UI framework that allows users to build web applications. Versions 1.2.2 and below contain a Path Traversal vulnerability that allows any user supplying an untrusted state_token through the UI stream payload to arbitrarily target files on the disk under the standard file-based runtime backend. This can result in application denial of service (via crash loops when reading non-msgpack target files as configurations), or arbitrary file manipulation. This vulnerability heavily exposes systems hosted utilizing FileStateSessionBackend. Unauthorized malicious actors could interact with arbitrary payloads overwriting or explicitly removing underlying service resources natively outside the application bounds. This issue has been fixed in version 1.2.3.

Metrics

CVSS 3.1

9.8/10

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

EPSS Probability

0.71%

48.9th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-22

Affected Software

Vendor	Product	Versions
Mesop-Dev	Mesop	< 1.2.3

References

https://github.com/mesop-dev/mesop/commit/c6b382f363b73ac32c402a2db3aadc7784f66a5bPatch
https://github.com/mesop-dev/mesop/releases/tag/v1.2.3Release Notes
https://github.com/mesop-dev/mesop/security/advisories/GHSA-8qvf-mr4w-9x2cExploit, Vendor Advisory
https://github.com/mesop-dev/mesop/security/advisories/GHSA-8qvf-mr4w-9x2cExploit, Vendor Advisory

Timeline

Published: Mar 20, 2026
Last Modified: Jun 17, 2026
Status: Analyzed

Frequently Asked Questions

What is CVE-2026-33054?

How severe is CVE-2026-33054?

CVE-2026-33054 has a CVSS score of 9.8/10 (CRITICAL severity). The EPSS model estimates a 0.71% probability of exploitation in the next 30 days.

How do I fix CVE-2026-33054?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2026-33054?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST