Vulnerability · Published Oct 30, 2026 · Assigned by GitHub_M

CVE-2026-55614uhttpd vulnerable to HTTP request smuggling via case-sensitive Transfer-Encoding matching

Medium 6.9

In plain English

A medium-severity security flaw in uhttpd from openwrt. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.4% (higher than 34% of all known vulnerabilities).

Severity (CVSS 4.0)6.9Medium

Exploit odds (30 days)0.4%top 66.1% of all CVEs

Exploited in the wildNo reportsnot in CISA KEV

Attack toolingNoneno public tooling known

Official 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.

Affected products (as reported)

Vendor	Product	Versions
openwrt	uhttpd	>= 2bef561c890f275ce3b785e6abdb3eda28c96aa8, < ae015e099986ceace44975cb69629841a2d58d37>= 2bef561c890f275ce3b785e6abdb3eda28c96aa8, < 6641b050e5f7c7fd9ae92e8e119d6d6dfc6e9837

Weakness: CWE-444 · 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

References

https://github.com/openwrt/uhttpd/security/advisories/GHSA-mcfg-c4r7-pjpf x_refsource_CONFIRM
https://github.com/openwrt/uhttpd/commit/6641b050e5f7c7fd9ae92e8e119d6d6dfc6e9837 x_refsource_MISC
https://github.com/openwrt/uhttpd/commit/ae015e099986ceace44975cb69629841a2d58d37 x_refsource_MISC