H2O-3GHSA-wwr9-4gmr-xvq9
H2O Vulnerable to Denial of Service (DoS) via `/3/Parse` Endpoint
High7.5CVE-2024-10549 · Published Mar 20, 2025 · updated Jul 7, 2026
A vulnerability in the `/3/Parse` endpoint of h2oai/h2o-3 version 3.46.0.1 allows for a denial of service (DoS) attack. The endpoint uses a user-specified string to construct a regular expression, which is then applied to another user-specified string. By sending multiple simultaneous requests, an attacker can exhaust all available threads, leading to a complete denial of service.
Affected versions
| Package | Affected | Fixed in |
|---|---|---|
| h2o PyPI | >= 3.30.0.7, <= 3.46.0.1 | No fix yet |
Details and references
More H2O-3 advisories
All H2O-3| Date | Advisory | Severity | Fixed in |
|---|---|---|---|
| Mar 202025 | H2O Vulnerable to Arbitrary File Overwrite High8.2Mar 20, 2025 | High8.2 | No fix yet |
| Mar 202025 | H2O Vulnerable to Denial of Service (DoS) via `HEAD` RequestHigh7.5Mar 20, 2025 | High7.5 | No fix yet |
| Mar 202025 | H2O Vulnerable to Denial of Service (DoS) via Large GZIP ParsingHigh7.5Mar 20, 2025 | High7.5 | No fix yet |
| Mar 202025 | H2O Vulnerable to Denial of Service (DoS) via `/3/ImportFiles` EndpointHigh7.5Mar 20, 2025 | High7.5 | No fix yet |
| Mar 202025 | H2O Vulnerable to Arbitrary File Overwrite via File ExportHigh7.1Mar 20, 2025 | High7.1 | No fix yet |
| Mar 202025 | H2O Vulnerable to Execution of Arbitrary FilesMedium6.5Mar 20, 2025 | Medium6.5 | No fix yet |