critical · 9.3 Patched

External Control of File Name or Path in h2oai/h2o-3

CVE-2023-6569 · GHSA-gqrq-j6pm-98c2 · PYSEC-2026-350 · published 14 Dec 2023

How serious is it

Severity: critical, CVSS score 9.3 out of 10.
No exploit prediction (EPSS) score yet.
Not on the CISA list of exploited vulnerabilities.
No public exploit in Exploit-DB.

Is your app affected by CVE-2023-6569?

Paste this prompt into Claude Code, Cursor or any AI coding tool: it runs a free Shippable scan of your project and fixes what it finds. Built with Lovable, Bolt or v0? Scan your live app. Or upload your package file.

Who is affected

h2o (PyPI) < 3.46.0.1

How to check

Run pip show h2o in your project to see the installed version, including copies pulled in by other packages.
Or paste your lockfile into the checker: it lists every package with a known vulnerability, this one included.
Or run npx shippable-dev scan localhost:3000 in your project folder. It reads your lockfile and flags this vulnerability along with every other known one.

How to fix

Copies a prompt for Claude Code, Cursor or Codex: it checks your lockfiles for this and upgrades it.

Upgrade h2o to 3.46.0.1 or later, commit the lockfile and redeploy.
If a vulnerable version was live, check your logs and rotate the secrets that server could read.

The advisory

Remote unauthenticated attackers can overwrite arbitrary server files with attacker-controllable data. The data that the attacker can control is not entirely arbitrary. h2o writes a CSV/XLS/etc file to disk, so the attacker data is wrapped in quotations and starts with "C1", if they're exporting as CSV.

Check your whole app

Dependencies are only half of it. Free and read-only: before you push, run npx shippable-dev scan localhost:3000 in your project folder, no account needed. For your live app, you prove it's yours with a one-line tag first.

References

Merged from GitHub Advisory Database, OSV. Last updated 28 Oct 2026. All vulnerabilities · RSS · JSON

Get alerts for new exploited vulnerabilities