# h2o.

Every CVE that names h2o among its affected products, newest first. Vendors and products are as the CNA wrote them.

## Records, newest first

- [h2o: heap exhaustion using capsules](https://agentprime.io/advisories/CVE-2026-55367.md)
  `CVE-2026-55367` · CVE record: h2o h2o · CVSS 7.5 High · Not analysed yet · Published 4 Nov 2026 · Tags: Denial of service
- [h2o: buffer overflow when using the %{error}x log directive](https://agentprime.io/advisories/CVE-2026-55368.md)
  `CVE-2026-55368` · CVE record: h2o h2o · CVSS 8.1 High · Not analysed yet · Published 4 Nov 2026 · Tags: Memory corruption
- [h2o has HTTP/2 state amplification](https://agentprime.io/advisories/CVE-2026-54340.md)
  `CVE-2026-54340` · CVE record: h2o h2o · CVSS 7.5 High · Not analysed yet · Published 16 Jul 2026 · Tags: Denial of service
- [h2o is vulnerable to musl libc stack overflow](https://agentprime.io/advisories/CVE-2026-44453.md)
  `CVE-2026-44453` · CVE record: h2o h2o · CVSS 7.5 High · Not analysed yet · Published 16 Jul 2026 · Tags: Denial of service
- [h2o is vulnerable to heap overrun](https://agentprime.io/advisories/CVE-2026-44452.md)
  `CVE-2026-44452` · CVE record: h2o h2o · CVSS 5.9 Medium · Not analysed yet · Published 16 Jul 2026 · Tags: Memory corruption, CWE-170
- [h2o: musl libc stack overflow (QPACK)](https://agentprime.io/advisories/CVE-2026-55213.md)
  `CVE-2026-55213` · CVE record: h2o h2o · CVSS 7.5 High · Not analysed yet · Published 10 Jul 2026 · Tags: Denial of service
- [H2O assertion failure when HTTP/3 requests are cancelled](https://agentprime.io/advisories/CVE-2024-45403.md)
  `CVE-2024-45403` · CVE record: h2o h2o · CVSS 3.7 Low · Not analysed yet · Published 11 Oct 2024 · Tags: Denial of service
- [H2O alllows bypassing address-based access control with 0-RTT](https://agentprime.io/advisories/CVE-2024-45397.md)
  `CVE-2024-45397` · CVE record: h2o h2o · CVSS 5.9 Medium · Not analysed yet · Published 11 Oct 2024 · Tags: Broken access control
- [H2O ignores headers configuration directives](https://agentprime.io/advisories/CVE-2024-25622.md)
  `CVE-2024-25622` · CVE record: h2o h2o · CVSS 3.1 Low · Not analysed yet · Published 11 Oct 2024 · Tags: CWE-670
- [h2o QUIC state exhaustion DoS](https://agentprime.io/advisories/CVE-2023-50247.md)
  `CVE-2023-50247` · CVE record: h2o h2o · CVSS 3.7 Low · Not analysed yet · Published 12 Dec 2023 · Tags: Denial of service
- [h2o vulnerable to TLS session resumption misdirection](https://agentprime.io/advisories/CVE-2023-41337.md)
  `CVE-2023-41337` · CVE record: h2o h2o · CVSS 6.1 Medium · Not analysed yet · Published 12 Dec 2023 · Tags: Weak cryptography or TLS
- [H2O vulnerable to read from uninitialized pointer in the reverse proxy handler](https://agentprime.io/advisories/CVE-2023-30847.md)
  `CVE-2023-30847` · CVE record: h2o h2o · CVSS 8.2 High · Not analysed yet · Published 27 Apr 2023 · Tags: Memory corruption
- [Unititialized memory access in h2o](https://agentprime.io/advisories/CVE-2021-43848.md)
  `CVE-2021-43848` · CVE record: h2o h2o · CVSS 7.4 High · Not analysed yet · Published 1 Feb 2022 · Tags: Memory corruption

## Filters and formats

Filters are query parameters on this URL: `q` (words, as in a web search engine: `"a phrase"`, `OR`, `-word`; an id; a package or product name), `severity` (low, medium, high or critical), `critical=1`, `kev=1`, `ecosystem` (npm, pypi, packagist, go, maven, rubygems, crates, nuget, hex), `kind=package`, `assigner` (a CNA’s short name), `min_score` and `state`. Each record’s title links to its Markdown page.

- The same list as JSON: <https://api.agentprime.io/v1/advisories?technology=h2o>
- Every list: <https://agentprime.io/advisories.md>, critical: <https://agentprime.io/advisories/critical.md>; by weakness: <https://agentprime.io/advisories/tag/sql-injection.md> and the other tags in <https://agentprime.io/llms.txt>; by technology: `/advisories/technology/<slug>.md` (`fortinet-fortimail`)

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The web page: <https://agentprime.io/advisories/technology/h2o/>. Everything for agents: <https://agentprime.io/llms.txt>.