CRLF injection vulnerability in the on_req function in lib/handler/redirect.c in H2O…
Priority LOW 21Published · Updated
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- High
- Impact type
- —
- Confidentiality · integrity · availability
- None · Low · None
- Fix status
- No fix listed
Attack profile from CVSS 3.0 · NVD. Fix status from CNA.
Summary
CRLF injection vulnerability in the on_req function in lib/handler/redirect.c in H2O before 1.6.2 and 1.7.x before 1.7.0-beta3 allows remote attackers to inject arbitrary HTTP headers and conduct HTTP response splitting attacks via a crafted URI.
Why it matters now
EPSS 0.01459 73rd 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 1.6.1 | Vulnerable | Kazuho Oku |
| cpe:2.3:a:dena:h2o:1.7.0:beta2:*:*:*:*:*:* | 1.7.0 beta2 | Vulnerable | Kazuho Oku |
- cpe:2.3:a:dena:h2o:*:*:*:*:*:*:*:* Versions up to 1.6.1 Vulnerable ·Kazuho Oku
- cpe:2.3:a:dena:h2o:1.7.0:beta2:*:*:*:*:*:* Versions 1.7.0 beta2 Vulnerable ·Kazuho Oku
Remediation
No fixed version listed by the sources yet.
Timeline
- 2026-10-02 Threatist record created from CVE-2016-1133
- 2026-10-03 Alias added: GHSA-mpq7-xv6q-mqgh
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-2016-04162 lib/http2/connection.c in H2O before 1.7.3 and 2.x before 2.0.0-beta5 mishandles HTTP/2… CVSS 3.0HIGH 7.5
- TI-2017-07997 Improper input validation in Kazuho Oku H2O CVSS 3.0HIGH 7.5
Sources
- CVE-2016-1133 · CVE Program
- CVE-2016-1133 · NVD
- FIRST EPSS
- GHSA-mpq7-xv6q-mqgh · 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