CVE-2026-54340 | High | 7.5 | 2026-07-17 | h2o is an HTTP server with support for HTTP/1.x, HTTP/2 and HTTP/3. Prior to commit 9265bdd, there is an HTTP/2 state amplification issue that combines HPACK d… |
CVE-2026-44453 | High | 7.5 | 2026-07-16 | h2o is an HTTP server with support for HTTP/1.x, HTTP/2 and HTTP/3. Prior to commit 6b5370d, h2o is vulnerable to a Denial of Service attack when calling alloc… |
CVE-2026-44452 | Medium | 5.9 | 2026-07-16 | h2o is an HTTP server with support for HTTP/1.x, HTTP/2 and HTTP/3. Prior to commit 8dc37cb, when h2o receives a ClientHello message over TLS or QUIC and it co… |
CVE-2026-44436 | High | 7.5 | 2026-07-16 | Quicly is an IETF QUIC protocol implementation intended primarily for use within the H2O HTTP server. Prior to commit 8b178e6, Quicly is vulnerable to a Denial… |
CVE-2026-44435 | High | 7.5 | 2026-07-16 | Quicly is an IETF QUIC protocol implementation intended primarily for use within the H2O HTTP server. Prior to commit 937d0e9, an assertion failure is raised w… |
CVE-2026-44434 | Medium | 5.3 | 2026-07-16 | Quicly is an IETF QUIC protocol implementation intended primarily for use within the H2O HTTP server. Prior to commit dccf5d4, Quicly was vulnerable to statele… |
CVE-2026-44433 | Medium | 5.3 | 2026-07-16 | Quicly is an IETF QUIC protocol implementation intended primarily for use within the H2O HTTP server. Prior to commit 8b178e6, an adversarial peer could send a… |
CVE-2026-55213 | High | 7.5 | 2026-07-10 | h2o is an HTTP server with support for HTTP/1.x, HTTP/2 and HTTP/3. Prior to commit edd7a120bfc4af11ac0cbebce2a43cc1f93f9af1, when h2o processes a QPACK instru… |
CVE-2026-8752 | Medium | 5.3 | 2026-05-17 | A weakness has been identified in h2oai h2o-3 up to 7402. This vulnerability affects the function exec of the file h2o-core/src/main/java/water/rapids/ast/prim… |
CVE-2026-8751 | High | 7.3 | 2026-05-17 | A security flaw has been discovered in h2oai h2o-3 up to 7402. This affects the function importBinaryModel of the file h2o-core/src/main/java/hex/Model.java of… |
CVE-2026-8750 | Medium | 5.3 | 2026-05-17 | A vulnerability was identified in h2oai h2o-3 up to 7402. Affected by this issue is the function importFiles of the file h2o-core/src/main/java/water/persist/P… |
CVE-2026-3960 | Critical | 9.8 | 2026-04-23 | A critical remote code execution vulnerability exists in the unauthenticated REST API endpoint /99/ImportSQLTable in H2O-3 version 3.46.0.9 and prior. The vuln… |
CVE-2025-61684 | High | 7.5 | 2026-01-19 | Quicly, an IETF QUIC protocol implementation, is susceptible to a denial-of-service attack prior to commit d9d3df6a8530a102b57d840e39b0311ce5c9e14e. A remote a… |
CVE-2025-10769 | Medium | 6.3 | 2025-09-21 | A vulnerability has been found in h2oai h2o-3 up to 3.46.08. This affects an unknown function of the file /99/ImportSQLTable of the component H2 JDBC Driver. S… |
CVE-2025-10768 | Medium | 6.3 | 2025-09-21 | A flaw has been found in h2oai h2o-3 up to 3.46.08. The impacted element is an unknown function of the file /99/ImportSQLTable of the component IBMDB2 JDBC Dri… |
CVE-2025-6544 | Critical | 9.8 | 2025-09-21 | A deserialization vulnerability exists in h2oai/h2o-3 versions <= 3.46.0.8, allowing attackers to read arbitrary system files and execute arbitrary code. The v… |
CVE-2024-8616 | High | 8.2 | 2025-03-20 | In h2oai/h2o-3 version 3.46.0, the `/99/Models/{name}/json` endpoint allows for arbitrary file overwrite on the target server. The vulnerability arises from th… |
CVE-2024-8062 | High | 7.5 | 2025-03-20 | A vulnerability in the typeahead endpoint of h2oai/h2o-3 version 3.46.0 allows for a denial of service. The endpoint performs a `HEAD` request to verify the ex… |
CVE-2024-7768 | High | 7.5 | 2025-03-20 | A vulnerability in the `/3/ImportFiles` endpoint of h2oai/h2o-3 version 3.46.1 allows an attacker to cause a denial of service. The endpoint takes a single GET… |
CVE-2024-7765 | High | 7.5 | 2025-03-20 | In h2oai/h2o-3 version 3.46.0.2, a vulnerability exists where uploading and repeatedly parsing a large GZIP file can cause a denial of service. The server beco… |
CVE-2024-6863 | Medium | 6.5 | 2025-03-20 | In h2oai/h2o-3 version 3.46.0, an endpoint exposing a custom EncryptionTool allows an attacker to encrypt any files on the target server with a key of their ch… |
CVE-2024-6854 | High | 7.1 | 2025-03-20 | In h2oai/h2o-3 version 3.46.0, the endpoint for exporting models does not restrict the export location, allowing an attacker to export a model to any file in t… |
CVE-2024-10572 | High | 7.5 | 2025-03-20 | In h2oai/h2o-3 version 3.46.0.1, the `run_tool` command exposes classes in the `water.tools` package through the `ast` parser. This includes the `XGBoostLibExt… |
CVE-2024-10553 | Critical | 9.8 | 2025-03-20 | A vulnerability in the h2oai/h2o-3 REST API versions 3.46.0.4 allows unauthenticated remote attackers to execute arbitrary code via deserialization of untruste… |
CVE-2024-10550 | High | 7.5 | 2025-03-20 | A vulnerability in the `/3/ParseSetup` endpoint of h2oai/h2o-3 version 3.46.0.1 allows for a denial of service (DoS) attack. The endpoint applies a user-specif… |
CVE-2024-10549 | High | 7.5 | 2025-03-20 | 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 stri… |
CVE-2024-45403 | Low | 3.7 | 2024-10-11 | h2o is an HTTP server with support for HTTP/1.x, HTTP/2 and HTTP/3. When h2o is configured as a reverse proxy and HTTP/3 requests are cancelled by the client… |
CVE-2024-45402 | High | 8.6 | 2024-10-11 | Picotls is a TLS protocol library that allows users select different crypto backends based on their use case. When parsing a spoofed TLS handshake message, pic… |
CVE-2024-45397 | Medium | 5.9 | 2024-10-11 | h2o is an HTTP server with support for HTTP/1.x, HTTP/2 and HTTP/3. When an HTTP request using TLS/1.3 early data on top of TCP Fast Open or QUIC 0-RTT packets… |
CVE-2024-45396 | High | 7.5 | 2024-10-11 | Quicly is an IETF QUIC protocol implementation. Quicly up to commtit d720707 is susceptible to a denial-of-service attack. A remote attacker can exploit these… |
CVE-2024-25622 | Low | 3.1 | 2024-10-11 | h2o is an HTTP server with support for HTTP/1.x, HTTP/2 and HTTP/3. The configuration directives provided by the headers handler allows users to modify the res… |
CVE-2024-8862 | High | 7.3 | 2024-09-14 | A vulnerability, which was classified as critical, has been found in h2oai h2o-3 3.46.0.4. This issue affects the function getConnectionSafe of the file /dtale… |
CVE-2024-45758 | Critical | 9.1 | 2024-09-06 | H2O.ai H2O through 3.46.0.4 allows attackers to arbitrarily set the JDBC URL, leading to deserialization attacks, file reads, and command execution. Exploitati… |
CVE-2024-5979 | High | 7.5 | 2024-06-27 | In h2oai/h2o-3 version 3.46.0, the `run_tool` command in the `rapids` component allows the `main` function of any class under the `water.tools` namespace to be… |
CVE-2024-5550 | Medium | 5.3 | 2024-06-06 | In h2oai/h2o-3 version 3.40.0.4, an exposure of sensitive information vulnerability exists due to an arbitrary system path lookup feature. This vulnerability a… |
CVE-2024-1456 | High | 7.1 | 2024-04-16 | An S3 bucket takeover vulnerability was identified in the h2oai/h2o-3 repository. The issue involves the S3 bucket 'http://s3.amazonaws.com/h2o-training', whic… |
CVE-2023-6569 | High | 8.2 | 2023-12-14 | External Control of File Name or Path in h2oai/h2o-3 |
CVE-2023-50247 | Low | 3.7 | 2023-12-12 | h2o is an HTTP server with support for HTTP/1.x, HTTP/2 and HTTP/3. The QUIC stack (quicly), as used by H2O up to commit 43f86e5 (in version 2.3.0-beta and pri… |
CVE-2023-41337 | Medium | 6.1 | 2023-12-12 | h2o is an HTTP server with support for HTTP/1.x, HTTP/2 and HTTP/3. In version 2.3.0-beta2 and prior, when h2o is configured to listen to multiple addresses or… |
CVE-2023-6038 | High | 7.5 | 2023-11-16 | A Local File Inclusion (LFI) vulnerability exists in the h2o-3 REST API, allowing unauthenticated remote attackers to read arbitrary files on the server with t… |
CVE-2023-6017 | High | 7.1 | 2023-11-16 | H2O included a reference to an S3 bucket that no longer existed allowing an attacker to take over the S3 bucket URL. |
CVE-2023-6013 | Medium | 5.4 | 2023-11-16 | H2O is vulnerable to stored XSS vulnerability which can lead to a Local File Include attack. |
CVE-2023-6016 | Critical | 9.8 | 2023-11-16 | An attacker is able to gain remote code execution on a server hosting the H2O dashboard through it's POJO model import feature. |
CVE-2023-30847 | High | 8.2 | 2023-04-27 | H2O is an HTTP server. In versions 2.3.0-beta2 and prior, when the reverse proxy handler tries to processes a certain type of invalid HTTP request, it tries to… |
CVE-2021-43848 | High | 7.4 | 2022-02-01 | h2o is an open source http server. In code prior to the `8c0eca3` commit h2o may attempt to access uninitialized memory. When receiving QUIC frames in certain… |