uhttpd is a small HTTP server. In unpatched repository snapshots, `client_parse_header()` in `client.c` lowercases header names but compares the `Transfer-Encoding` value to `chunked` using case-sensitive `strcmp`. A mixed-case transfer-coding token is accepted without enabling `r->transfer_chunked`, despite transfer-coding tokens being case-insensitive. On a keep-alive connection, the `chunked` POST body is left unread and request-shaped body bytes are parsed as another HTTP request, permitting HTTP request smuggling and boundary desynchronization. Commits ae015e099986ceace44975cb69629841a2d58d37 and 6641b050e5f7c7fd9ae92e8e119d6d6dfc6e9837 patch the issue.

Metrics

Attack Vector Network

Attack Complexity Low

Privileges Required None

Attack Requirements None

User Interaction None

Vulnerable System Confidentiality Impact None

Vulnerable System Integrity Impact Low

Vulnerable System Availability Impact None

Subsequent System Confidentiality Impact None

Subsequent System Integrity Impact None

Subsequent System Availability Impact None

No CVSS v3.1

No CVSS v3.0

No CVSS v2

This CVE is not in the KEV list.

No EPSS score available.

Key SSVC decision points have not yet been added.

Affected Vendors & Products

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Advisories

No advisories yet.

Fixes

Solution

No solution given by the vendor.

Workaround

No workaround given by the vendor.

References
Link Providers
https://github.com/openwrt/uhttpd/commit/6641b050e5f7c7fd9ae92e8e119d6d6dfc6e9837 cve-icon cve-icon
https://github.com/openwrt/uhttpd/commit/ae015e099986ceace44975cb69629841a2d58d37 cve-icon cve-icon
https://github.com/openwrt/uhttpd/security/advisories/GHSA-mcfg-c4r7-pjpf cve-icon cve-icon
History

Fri, 30 Oct 2026 22:15:00 +0000

Type Values Removed Values Added
Description uhttpd is a small HTTP server. In unpatched repository snapshots, `client_parse_header()` in `client.c` lowercases header names but compares the `Transfer-Encoding` value to `chunked` using case-sensitive `strcmp`. A mixed-case transfer-coding token is accepted without enabling `r->transfer_chunked`, despite transfer-coding tokens being case-insensitive. On a keep-alive connection, the `chunked` POST body is left unread and request-shaped body bytes are parsed as another HTTP request, permitting HTTP request smuggling and boundary desynchronization. Commits ae015e099986ceace44975cb69629841a2d58d37 and 6641b050e5f7c7fd9ae92e8e119d6d6dfc6e9837 patch the issue.
Title uhttpd vulnerable to HTTP request smuggling via case-sensitive Transfer-Encoding matching
Weaknesses CWE-444
References
Metrics cvssV4_0

{'score': 6.9, 'vector': 'CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N'}

Projects

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cve-icon MITRE

Status: PUBLISHED

Assigner: GitHub_M

Published:

Updated: 2026-10-30T22:01:54.750Z

Reserved: 2026-06-16T23:31:22.445Z

Link: CVE-2026-55614

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Received

Published: 2026-10-30T22:16:55.250

Modified: 2026-10-30T22:16:55.250

Link: CVE-2026-55614

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2026-10-30T23:30:15Z

Weaknesses