How severe is CVE-2021-43831?

CVE-2021-43831 has a CVSS score of 7.7/10, rated HIGH. Immediate patching is strongly recommended.

Which packages are affected by CVE-2021-43831?

CVE-2021-43831 affects the following packages: gradio (PyPI). Ecosystems affected: PyPI.

How do I fix CVE-2021-43831?

Update gradio to 2.5.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2021-43831 is resolved across your whole dependency graph.

How do I detect CVE-2021-43831 in my PyPI dependencies?

Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for gradio. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.

How do I mitigate CVE-2021-43831 if there is no patch (or I can't update yet)?

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 does O3 Security protect against CVE-2021-43831?

O3 pinpoints whether CVE-2021-43831 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.

Is CVE-2021-43831 actively exploited in the wild?

Yes. There are 1 known exploit references for CVE-2021-43831, including 1 in-the-wild exploitation observed on GitHub and other sources. Treat this as actively exploitable and prioritize patching immediately. All exploit code should only be run in an isolated sandbox environment for research or authorized testing — never against production systems without explicit written authorization.

What is the EPSS score for CVE-2021-43831?

CVE-2021-43831 has an EPSS (Exploit Prediction Scoring System) score of 3.8%, placing it in the 89th percentile of all CVEs. EPSS is maintained by FIRST.org and estimates the probability that a vulnerability will be exploited in the wild within the next 30 days. This score indicates relatively lower exploitation probability, though the CVSS severity should still guide your patching priority.

Is there exploit tooling available for CVE-2021-43831?

A Nuclei detection template exists for CVE-2021-43831, meaning automated scanners can fingerprint it. Public exploit tooling significantly increases real-world risk — prioritize patching and ensure detection coverage. Exploit tooling should only ever be used in isolated, authorized testing environments.

When was CVE-2021-43831 published, and has it been updated?

CVE-2021-43831 was published on December 15, 2021 and was last updated on March 13, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

CVE-2021-43831: gradio (High 7.7)

EPSS Exploitation Probability

via FIRST.org ↗

3.8%probability of exploitation in next 30 days

Lower Risk89th percentile-26.55%

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.

Blast Radius

1 pkg affected

🐍gradio

Real-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

Gradio is an open source framework for building interactive machine learning models and demos. In versions prior to 2.5.0 there is a vulnerability that affects anyone who creates and publicly shares Gradio interfaces. File paths are not restricted and users who receive a Gradio link can access any files on the host computer if they know the file names or file paths. This is limited only by the host operating system. Paths are opened in read only mode. The problem has been patched in gradio 2.5.0.

Affected Packages

1 total 1 fixed

Ecosystem	Package	Vulnerable range	Fix
🐍PyPI	`gradio`	all versions	2.5.0

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for gradio. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Fix
Update gradio to 2.5.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2021-43831 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 pinpoints whether CVE-2021-43831 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.

Tailored to CVE-2021-43831. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.

Frequently Asked Questions

Gradio is an open source framework for building interactive machine learning models and demos. In versions prior to 2.5.0 there is a vulnerability that affects anyone who creates and publicly shares Gradio interfaces. File paths are not restricted and users who receive a Gradio link can access any files on the host computer if they know the file names or file paths. This is limited only by the host operating system. Paths are opened in read only mode. The problem has been patched in gradio 2.5.0.

O3 Security · Impact-Aware SCA

Is CVE-2021-43831 in your dependencies?

O3 detects CVE-2021-43831 across PyPI dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.

Scan my dependencies How O3 SCA works

CVE-2021-43831