Vulnerability Database

328,409

Total vulnerabilities in the database

Vulnerabilities for products matching "h2o"

Found 4 matching products. Filters apply to all results.

You can search for specific versions with /product/h2o/1.2.3

dena / h2o

17 vulnerabilities found
Title Severity Exploit Date Affected Version
Low October 11, 2024 10/11/24
>= 2024-06-18 < 2024-09-04
Medium October 11, 2024 10/11/24
< 2024-10-10
Low October 11, 2024 10/11/24
<= 2024-02-11
Low December 12, 2023 12/12/23
<= 2.2.6
== 2.3.0-beta1
== 2.3.0-beta2
Medium December 12, 2023 12/12/23
<= 2.2.6
== 2.3.0-beta1
== 2.3.0-beta2
High October 10, 2023 10/10/23
< 2023-10-10
High April 27, 2023 4/27/23
<= 2.2.6
== 2.3.0-beta1
== 2.3.0-beta2
High February 1, 2022 2/1/22
< 2021-12-20
High June 26, 2018 6/26/18
<= 2.2.4
High December 22, 2017 12/22/17
< 2.2.3
Medium December 22, 2017 12/22/17
<= 2.2.2
Low December 22, 2017 12/22/17
<= 2.2.3
Medium December 22, 2017 12/22/17
<= 2.2.3
Medium June 9, 2017 6/9/17
<= 2.0.4
Medium May 12, 2017 5/12/17
>= 2.0.0 <= 2.0.3
== 2.1.0
== 2.1.0-beta1
Medium June 19, 2016 6/19/16
<= 1.7.2
<= 2.0.0
Low January 16, 2016 1/16/16
<= 1.6.1
== 1.7.0-beta2

h2o_project / h2o

1 vulnerabilities found
Title Severity Exploit Date Affected Version
Medium June 9, 2017 6/9/17
== 2.1.0-beta3

h2o / h2o

19 vulnerabilities found
Title Severity Exploit Date Affected Version
Medium September 21, 2025 9/21/25
>= 3.0.0.2 <= 3.46.0.8
Medium September 21, 2025 9/21/25
>= 3.0.0.2 <= 3.46.0.8
Critical September 21, 2025 9/21/25
>= 3.0.0.2 <= 3.46.0.8
High March 20, 2025 3/20/25
== 3.46.0
High March 20, 2025 3/20/25
== 3.46.0
High March 20, 2025 3/20/25
== 3.46.1
High March 20, 2025 3/20/25
== 3.46.0.2
Medium March 20, 2025 3/20/25
== 3.46.0
High March 20, 2025 3/20/25
== 3.46.0
High March 20, 2025 3/20/25
== 3.46.0.1
Critical March 20, 2025 3/20/25
== 3.46.0.4
High March 20, 2025 3/20/25
== 3.46.0.1
High March 20, 2025 3/20/25
== 3.46.0.1
High September 14, 2024 9/14/24
== 3.46.0.4
Critical September 6, 2024 9/6/24
<= 3.46.0.4
High June 27, 2024 6/27/24
== 3.46.0
Medium June 6, 2024 6/6/24
== 3.40.0.4
Unknown April 16, 2024 4/16/24
== 3.45.0.6386
High December 14, 2023 12/14/23
== 3.40.0.4
Python icon

h2o

15 vulnerabilities found
Title Severity Exploit Date Affected Version
Critical February 2, 2026 2/2/26
<= 3.46.0.1
Critical September 21, 2025 9/21/25
<= 3.46.0.7
High March 20, 2025 3/20/25
>= 3.10.4.1 <= 3.46.0
High March 20, 2025 3/20/25
>= 3.2.0.1 <= 3.46.0
High March 20, 2025 3/20/25
<= 3.46.1
High March 20, 2025 3/20/25
>= 3.32.1.2 <= 3.46.0.2
High March 20, 2025 3/20/25
>= 3.32.1.1 <= 3.46.0
Medium March 20, 2025 3/20/25
>= 3.32.1.2 <= 3.46.0
High March 20, 2025 3/20/25
>= 3.30.0.7 <= 3.46.0.1
Critical March 20, 2025 3/20/25
< 3.46.0.6
High March 20, 2025 3/20/25
>= 3.34.0.1 <= 3.46.0.1
High March 20, 2025 3/20/25
>= 3.30.0.7 <= 3.46.0.1
High June 27, 2024 6/27/24
<= 3.46.0
Medium June 6, 2024 6/6/24
<= 3.40.0.4
High December 14, 2023 12/14/23
<= 3.44.0.2

Showing vulnerabilities for 4 products matching "h2o". Each product has independent pagination.

Frequently Asked Questions

A security vulnerability is a weakness in software, hardware, or configuration that can be exploited to compromise confidentiality, integrity, or availability. Many vulnerabilities are tracked as CVEs (Common Vulnerabilities and Exposures), which provide a standardized identifier so teams can coordinate patching, mitigation, and risk assessment across tools and vendors.

CVSS (Common Vulnerability Scoring System) estimates technical severity, but it doesn't automatically equal business risk. Prioritize using context like internet exposure, affected asset criticality, known exploitation (proof-of-concept or in-the-wild), and whether compensating controls exist. A "Medium" CVSS on an exposed, production system can be more urgent than a "Critical" on an isolated, non-production host.

A vulnerability is the underlying weakness. An exploit is the method or code used to take advantage of it. A zero-day is a vulnerability that is unknown to the vendor or has no publicly available fix when attackers begin using it. In practice, risk increases sharply when exploitation becomes reliable or widespread.

Recurring findings usually come from incomplete Asset Discovery, inconsistent patch management, inherited images, and configuration drift. In modern environments, you also need to watch the software supply chain: dependencies, containers, build pipelines, and third-party services can reintroduce the same weakness even after you patch a single host. Unknown or unmanaged assets (often called Shadow IT) are a common reason the same issues resurface.

Use a simple, repeatable triage model: focus first on externally exposed assets, high-value systems (identity, VPN, email, production), vulnerabilities with known exploits, and issues that enable remote code execution or privilege escalation. Then enforce patch SLAs and track progress using consistent metrics so remediation is steady, not reactive.

SynScan combines attack surface monitoring and continuous security auditing to keep your inventory current, flag high-impact vulnerabilities early, and help you turn raw findings into a practical remediation plan.