lib/http2/connection.c in H2O before 1.7.3 and 2.x before 2.0.0-beta5 mishandles HTTP/2…
Priority MEDIUM 40Published · Updated
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- Low
- Impact type
- —
- Confidentiality · integrity · availability
- None · None · High
- Fix status
- No fix listed
Attack profile from CVSS 3.0 · NVD. Fix status from CNA.
Summary
lib/http2/connection.c in H2O before 1.7.3 and 2.x before 2.0.0-beta5 mishandles HTTP/2 disconnection, which allows remote attackers to cause a denial of service (use-after-free and application crash) or possibly execute arbitrary code via a crafted packet.
Why it matters now
EPSS 0.04448 91st percentileScored 2026-11-07
Fix No fix listed No fixed version in the sources yet
SSVC decision points
Not available: CISA has not published SSVC decision points for this record.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| — | — | all versions | — | No fix listed | CNA |
- — Vendor— Affected all versions Fixed in — No fix listed CNA
CPE configurations NVD · 2
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:a:dena:h2o:*:*:*:*:*:*:*:* | up to 1.7.2 | Vulnerable | Kazuho Oku |
| cpe:2.3:a:dena:h2o:*:beta4:*:*:*:*:*:* | up to 2.0.0 | Vulnerable | Kazuho Oku |
- cpe:2.3:a:dena:h2o:*:*:*:*:*:*:*:* Versions up to 1.7.2 Vulnerable ·Kazuho Oku
- cpe:2.3:a:dena:h2o:*:beta4:*:*:*:*:*:* Versions up to 2.0.0 Vulnerable ·Kazuho Oku
Remediation
No fixed version listed by the sources yet.
Timeline
- 2026-10-02 Threatist record created from CVE-2016-4817
- 2026-10-03 Alias added: GHSA-32wr-c4w3-hg28
References
More Kazuho Oku H2o vulnerabilities
- TI-2023-23979 The HTTP/2 protocol allows a denial of service (server resource consumption) because… KEVCVSS 3.1HIGH 7.5
- TI-2018-00565 Memory corruption in Kazuho Oku H2O CVSS 3.0CRITICAL 9.8
- TI-2016-06584 Use after free in Kazuho Oku H2O CVSS 3.0CRITICAL 9.1
- TI-2023-14626 H2O vulnerable to read from uninitialized pointer in the reverse proxy handler CVSS 3.1HIGH 8.2
- TI-2017-07997 Improper input validation in Kazuho Oku H2O CVSS 3.0HIGH 7.5
- TI-2017-07966 Improper input validation in Kazuho Oku H2O CVSS 3.1HIGH 7.5
Sources
- CVE-2016-4817 · CVE Program
- CVE-2016-4817 · NVD
- FIRST EPSS
- GHSA-32wr-c4w3-hg28 · GitHub Advisory Database · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences