Security Digest · Vulnerability record
CVE-2024-5986: H2O has an External Control of File Name or Path vulnerability
A vulnerability in h2oai/h2o-3 version 3.46.0.1 allows remote attackers to write arbitrary data to any file on the server.
CVSS 9.1 Critical EPSS 0.7% · p53
Should you act?
Critical and remotely reachable
No known exploitation yet, but it is network-reachable without credentials. This signal is computed from CISA KEV, EPSS and CVSS data; it is not an editorial verdict.
- No confirmed exploitation. It is not in CISA’s KEV catalog and CISA’s SSVC assessment records no known exploitation. That can change quickly after a public write-up; re-check if you are affected.
- EPSS 0.7%, percentile 53: FIRST’s model estimates a 0.7% chance of exploitation activity in the next 30 days, higher than 53% of all scored CVEs (moderate). EPSS is a probability, not a verdict.
- Remotely reachable with no login and no user interaction. If the vulnerable service is exposed to the internet, prioritize it.
- Only applies if your dependency tree includes
ai.h2o:h2o-core(Maven) <= 3.46.0.1, no fixed version listed;h2o(PyPI) <= 3.46.0.1, no fixed version listed. Check your lockfile, including transitive dependencies.
What it is
A vulnerability in h2oai/h2o-3 version 3.46.0.1 allows remote attackers to write arbitrary data to any file on the server. This is achieved by exploiting the /3/Parse endpoint to inject attacker-controlled data as the header of an empty file, which is then exported using the /3/Frames/framename/export endpoint. The impact of this vulnerability includes the potential for remote code execution and complete access to the system running h2o-3, as attackers can overwrite critical files such as private SSH keys or script files.
From the GitHub advisory
A vulnerability in h2oai/h2o-3 version 3.46.0.1 allows remote attackers to write arbitrary data to any file on the server. This is achieved by exploiting the /3/Parse endpoint to inject attacker-controlled data as the header of an empty file, which is then exported using the /3/Frames/framename/export endpoint. The impact of this vulnerability includes the potential for remote code execution and complete access to the system running h2o-3, as attackers can overwrite critical files such as private SSH keys or script files.
Weakness type: CWE-73.
Product: ai.h2o:h2o-core (Maven) · Assigned by: @huntr_ai · Published: 2026-02-02
Affected and fixed versions
| Ecosystem | Package | Vulnerable | First fixed |
|---|---|---|---|
| Maven | ai.h2o:h2o-core | <= 3.46.0.1 | none listed |
| PyPI | h2o | <= 3.46.0.1 | none listed |
| Vendor | Product | Affected versions (per CVE record) |
|---|---|---|
| h2oai | h2oai/h2o-3 | unspecified <= latest |
Severity scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| @huntr_ai | 3.0 | 9.1 Critical | CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:H |
| GitHub | 3.1 | 9.1 | CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:H |
- Attack vector: network (remotely reachable)
- Attack complexity: low
- Privileges required: none (no login)
- User interaction: none
- Scope: unchanged
CVSS measures how bad a flaw is if exploited, not how likely exploitation is. Read it next to the exploitation data below.
Exploitation and urgency
- CISA KEV: not listed (no confirmed in-the-wild exploitation known to CISA).
- CISA SSVC assessment: exploitation none, automatable yes, technical impact total.
- FIRST EPSS (model of 2026-10-21): 0.71% probability of exploitation activity in the next 30 days; percentile 53.
Timeline
- — CVE record last updated
- — CVE record published by @huntr_ai
- — GitHub-reviewed advisory GHSA-wj3h-wx8g-x699 published (critical)
Sources and references
Original sources first. Version and fix details should always be confirmed against the vendor or project advisory.
Vulnerability records
- GitHub Advisory GHSA-wj3h-wx8g-x699 github.com
- CVE.org record CVE-2024-5986 cve.org
- NVD entry CVE-2024-5986 nvd.nist.gov
Other references from the CVE record and advisory
- huntr.com huntr.com