HIGHVulnerability
CVE-2026-54340
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 decompression amplification with Slowloris-style stream stalling. Amplified decoded header state can be retained by stalled HTTP/2 streams, and depending on the configuration, additional limits are needed to bound decoded header state and prevent attack. This issue has been fixed by commit 9265bdd.
Properties
- severity
- HIGH
- score
- 7.5
- cve_id
- CVE-2026-54340
- vector
- CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
- published_at
- 2026-07-17T00:16:25.810
- last_modified
- 2026-08-05T19:47:02.317
Related Entities (4)
HAS_WEAKNESS (2)
→[Weakness]Allocation of Resources Without Limits or Throttling
→[Weakness]Uncontrolled Resource Consumption
DESCRIBED_BY (1)
→[Source]NVD
AFFECTS_PRODUCT (1)
→[Product]
Explore deeper with Ninja Signal's threat intelligence graph