CVE-2026-38969

webrick: rubygem-webrick: WEBrick: Request smuggling via re-parsing of Content-Length header

Published Jul 2, 2026 CVSS 3.1 · 6.5 Medium EPSS n/a KEV · Not listed
Description
DO NOT USE THIS CVE RECORD. ConsultIDs: none. Reason: This record was withdrawn by its CNA. Further investigation showed that it was not a security issue. Notes: none.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

No advisories available
History
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'yes', 'Exploitation': 'poc', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

cvssV3_1

{'score': 7.5, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N'}

cvssV3_1

{'score': 6.5, 'vector': 'CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:L'}

Type Values Removed Values Added
Description ruby webrick through v1.9.2 WEBrick reparses trailer Content-Length into canonical request state, enabling request smuggling. NOTE: the Supplier reports that "The project README states that it is suitable for testing and development, and that its developers do not encourage its use to serve production web applications that may be subject to hostile input. It is not a production web server and is not intended to receive traffic from untrusted sources. Request smuggling is only reachable when WEBrick sits behind a proxy and receives hostile traffic in a production deployment, which is the configuration the project documents as discouraged." DO NOT USE THIS CVE RECORD. ConsultIDs: none. Reason: This record was withdrawn by its CNA. Further investigation showed that it was not a security issue. Notes: none.
References
Type Values Removed Values Added
Description ruby webrick through v1.9.2 WEBrick reparses trailer Content-Length into canonical request state, enabling request smuggling. ruby webrick through v1.9.2 WEBrick reparses trailer Content-Length into canonical request state, enabling request smuggling. NOTE: the Supplier reports that "The project README states that it is suitable for testing and development, and that its developers do not encourage its use to serve production web applications that may be subject to hostile input. It is not a production web server and is not intended to receive traffic from untrusted sources. Request smuggling is only reachable when WEBrick sits behind a proxy and receives hostile traffic in a production deployment, which is the configuration the project documents as discouraged."
References
Type Values Removed Values Added
Metrics cvssV3_1

{'score': 6.5, 'vector': 'CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:L'}

ssvc

{'options': {'Automatable': 'yes', 'Exploitation': 'poc', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

cvssV3_1

{'score': 7.5, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N'}

Type Values Removed Values Added
Weaknesses CWE-20
Type Values Removed Values Added
Title WEBrick Request Smuggling via Trailer Content-Length Re‑parsing webrick: rubygem-webrick: WEBrick: Request smuggling via re-parsing of Content-Length header
Weaknesses CWE-444
References
Metrics threat_severity

None

cvssV3_1

{'score': 6.5, 'vector': 'CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:L'}

threat_severity

Moderate

Type Values Removed Values Added
Title WEBrick Request Smuggling via Trailer Content-Length Re‑parsing
Weaknesses CWE-20
Type Values Removed Values Added
First Time appeared Ruby
Ruby webrick
Vendors & Products Ruby
Ruby webrick
Type Values Removed Values Added
Description ruby webrick through v1.9.2 WEBrick reparses trailer Content-Length into canonical request state, enabling request smuggling.
References
Weaknesses

Sources

Status
REJECTED
Assigner
mitre
Published
Updated
Jul 14, 2026, 4:58 PM
Reserved
Apr 6, 2026, 12:00 AM
Status
Rejected
Published
Jul 2, 2026, 9:16 PM
Modified
Jul 14, 2026, 5:16 PM
Severity
Moderate
Public date
Jul 2, 2026, 12:00 AM