GHSA-pmv9-3xqp-8w42 is a high-severity (CVSS 7.5) vulnerability in mesop. A fix is available for mesop — see the affected versions and patch details below.
Mesop has a local file Inclusion via static file serving functionality
Exploitation Status
No confirmed exploitation observed yet
- CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.
Exploitation and automatability from CISA’s SSVC triage for GHSA-pmv9-3xqp-8w42.
EPSS Exploitation Probability
EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.
How urgent is this, really
GHSA-pmv9-3xqp-8w42 plotted by exploitation likelihood (EPSS) against impact (CVSS). The shaded corner — EPSS 50%+ and CVSS 7.0+ — is where this CVE doesn't sit, though severity or exploitability alone can still warrant action.
Where this sits among everything scored
Of 379,145 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Real counts from FIRST.org, not a sample — log-scaled since the landscape is heavily right-skewed.
Real-World Exposure
mesopReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects PyPI packages — download data is not available via public APIs for these ecosystems.
Description
A vulnerability has been discovered and fixed in Mesop that could potentially allow unauthorized access to files on the server hosting the Mesop application. The vulnerability was related to insufficient input validation in a specific endpoint. This could have allowed an attacker to access files not intended to be served.
Users are strongly advised to update to the latest version of Mesop immediately. The latest version includes a fix for this vulnerability.
We would like to thank @Letm3through for reporting this issue and proposing mitigations to address this issue.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐍PyPI | mesop | ≥ 0.9.0&&< 0.12.4 | 0.12.4pip install --upgrade 'mesop==0.12.4' |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for mesop, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update mesop to 0.12.4 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-pmv9-3xqp-8w42 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like GHSA-pmv9-3xqp-8w42 can be triaged on real exposure rather than presence alone.
Tailored to GHSA-pmv9-3xqp-8w42. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is GHSA-pmv9-3xqp-8w42 in your dependencies?
O3 Security finds GHSA-pmv9-3xqp-8w42 across PyPI dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.