CVE-2026-55613

The record

uhttpd is a small HTTP server. In unpatched repository snapshots, `uh_ubus_data_send()` in `ubus.c` can desynchronize HTTP request boundaries when a `POST /ubus` JSON body arrives in multiple TCP segments. An initial segment completing a JSON object sets `du->jsobj`; a later segment takes the existing-object parse-error path and returns zero bytes consumed. The caller neither drains the remaining declared `Content-Length` nor sets `connection_close`. An HTTP request embedded in the unread body suffix is consequently processed as a new request on the same keep-alive connection. The reported reproducer returned a JSON-RPC parse error followed by a second HTTP response. This application-layer body-handler flaw is distinct from Transfer-Encoding header case handling and chunk-length state reset, and affects deployments enabling ubus, including the default OpenWrt configuration and potential proxy/CDN deployments. Repository patches 7b1bec45826bd78c8afc993435bdc0f1df2fe399 and b2285de129b9adc8b12f84f9a27c16c21f2b57a5 address this issue.

Affected packages

Related vulnerabilities

• CVE-2026-55614 uhttpd is a small HTTP server. CWE-444
• CVE-2026-55612 uhttpd is a small HTTP server. CWE-444
• CVE-2026-116127 Starlet versions before 0.33 for Perl send a body in responses to HEAD requests… CWE-444
• CVE-2026-91920 A flaw was found in the ChunkReader component of the Undertow web server, which is used… CWE-444
• CVE-2026-118264 Echo is a Go web framework. CWE-444
• CVE-2026-103995 Response body and chunk parsing would handle non-hex or negative integers incorrectly… CWE-444
• CVE-2026-115823 Starman versions before 0.4019 for Perl send response bodies for HEAD requests… CWE-444
• CVE-2026-115877 Twisted is an event-based framework for internet applications, supporting Python 3.6+. CWE-444