CVE-2026-55613 (GCVE-0-2026-55613)
Vulnerability from cvelistv5 – Published: 2026-10-30 21:57 – Updated: 2026-11-05 02:55
VLAI
EPSS
VEX
Title
uhttpd: HTTP request smuggling via ubus POST body parse-error desync
Summary
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.
Severity
SSVC
Exploitation: poc
Automatable: yes
Technical Impact: partial
CISA Coordinator · CISA-ADP (v2.0.3)
Decision recorded 2026-11-05 02:55 UTC
CWE
- CWE-444 - Inconsistent Interpretation of HTTP Requests ('HTTP Request/Response Smuggling')
Assigner
References
3 references
| URL | Tags |
|---|---|
| https://github.com/openwrt/uhttpd/security/adviso… | x_refsource_CONFIRM |
| https://github.com/openwrt/uhttpd/commit/7b1bec45… | x_refsource_MISC |
| https://github.com/openwrt/uhttpd/commit/b2285de1… | x_refsource_MISC |
Impacted products
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