CVE-2026-33054: Mesop is a Python-based UI framework that allows users to build web applications

This week

CRITICAL 10.0REMOTEUPGRADE

CVE-2026-33054 is a critical-severity flaw (CVSS 10.0) affecting mesop. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

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 arbi

Why this priority

Critical severity
Public exploit reference
CISA SSVC: automatable with total technical impact
Remotely exploitable, no login, no user action

A fixed release or distro patch exists.

Risk facts

CVSS score	10.0 (Critical)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	None
EPSS exploit chance	0.7% (top 46%)
CISA exploited list	No
Weakness	CWE-22
Published	2026-03-20
Last modified	2026-06-17

Publisher (CNA): GitHub, Inc. · Vendor: mesop-dev

Last updated 2026-06-17 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2026-03-20 07:16 UTCPublished CVE record published
2026-06-17 10:36 UTCUpdated Record last modified

mesop-dev mesop UPGRADE

Affected: < 1.2.3

Fixed in: 1.2.3

Safe to downgrade to: no unaffected older release

1. Check installed version

apt-cache policy mesop || rpm -q mesop || mesop --version

2. UPGRADE to 1.2.3 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade mesop

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade mesop

Note

Distros often backport fixes without changing the version number. Confirm with the distro advisory or changelog.

Exact fixes by distribution

Python (pip) · mesop · FIXED · 1.2.3 · vulnerable: <= 1.2.2 · source

pip install --upgrade "mesop>=1.2.3" pip show mesop

Fedora ELN · fonttools · FIXED · 4.68.0-1.eln159 · FEDORA-2026-37fa4b964c · source

sudo dnf upgrade --advisory=FEDORA-2026-37fa4b964c

Fedora 46 · fonttools · FIXED · 4.68.0-1.fc46 · FEDORA-2026-65d6c01c75 · source

sudo dnf upgrade --advisory=FEDORA-2026-65d6c01c75

Public exploits and detection

Public code exists for this CVE. Treat unpatched systems as at risk, and only run PoCs in a lab.

Write-up: github.com/mesop-dev/mesop/security/advisories/GHSA-8qvf-mr4w-9x2c

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2026-33054?

mesop: upgrade to 1.2.3. Exact commands for each OS are on this page.

Is CVE-2026-33054 being exploited?

CVE-2026-33054 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2026-33054 affect?

CVE-2026-33054 affects mesop. Severity is critical (CVSS 10.0). 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 arbit

How urgent is CVE-2026-33054?

Priority 61/100. Critical severity; Public exploit reference; CISA SSVC: automatable with total technical impact; Remotely exploitable, no login, no user action

Software pages

Python vulnerabilities

Related CVEs

CVE-2026-34824 HIGH 7.5 UPGRADE Mesop is a Python-based UI framework that allows users to build web applications
CVE-2026-33057 CRITICAL 9.8 UPGRADE Mesop is a Python-based UI framework that allows users to build web applications

References

← Back to latest CVEs