Quick answers
- Is CVE-2026-8750 exploited in the wild?
- No. Junglewise Threat Intelligence has no report of CVE-2026-8750 being exploited in the wild.
- How severe is CVE-2026-8750?
- Medium severity, with a CVSS score of 5.3, published 17 May 2026.
- Which products and versions are affected?
- H2O.ai H2O-3 up to 7402.
- Is there a fix for CVE-2026-8750?
- No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.
- How is CVE-2026-8750 attacked?
- It is attacked over the network, in a software library.
- Am I affected by CVE-2026-8750?
- Check whether you run H2O.ai H2O-3 at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.
Technical details
A path traversal vulnerability exists in the `importFiles` function within `h2o-core/src/main/java/water/persist/PersistNFS.java`. The `POST /3/ImportFiles` endpoint is exposed without authentication and accepts attacker-controlled filesystem paths. While the application implements a 'deny-glob' blacklist (blocking directories like /etc and /proc), it fails to restrict access to other sensitive local paths. An unauthenticated attacker can use this endpoint to import a local file as an H2O frame and subsequently retrieve the file's contents via the `GET /3/Frames/` API. The vulnerability stems from trusting user-supplied absolute paths and relying on an incomplete blacklist-based security model.
Affected products
- h2oai h2o-3 up to 7402
Timeline
- 2026-05-17: advisory: Vulnerability published by NVD/VulDB