uhttpd is a small HTTP server. In unpatched repository snapshots, `client_poll_post_data()` in `client.c` consumes an invalid chunk-length line, such as a size exceeding INT_MAX, then clears `r->content_length` and `r->transfer_chunked` without draining the remaining body or setting `request.connection_close`. The completion check treats the chunked POST as finished and the keep-alive parser returns to `CLIENT_STATE_INIT`. Attacker-controlled body bytes aligned as a complete HTTP request are then parsed and processed as another request on the same connection, causing HTTP request smuggling and request-boundary desynchronization. Commits b78f518478794e16ba3568fc1258e40bf3e8eb3b and 34460b8211d676ef1b9f40d6b775c5e112933690 patch the issue.
Metrics
Affected Vendors & Products
References
History
Tue, 03 Nov 2026 17:00:00 +0000
| Type | Values Removed | Values Added |
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| First Time appeared |
Openwrt
Openwrt uhttpd |
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| Vendors & Products |
Openwrt
Openwrt uhttpd |
Mon, 02 Nov 2026 19:30:00 +0000
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| Metrics |
ssvc
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Fri, 30 Oct 2026 22:15:00 +0000
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| Description | uhttpd is a small HTTP server. In unpatched repository snapshots, `client_poll_post_data()` in `client.c` consumes an invalid chunk-length line, such as a size exceeding INT_MAX, then clears `r->content_length` and `r->transfer_chunked` without draining the remaining body or setting `request.connection_close`. The completion check treats the chunked POST as finished and the keep-alive parser returns to `CLIENT_STATE_INIT`. Attacker-controlled body bytes aligned as a complete HTTP request are then parsed and processed as another request on the same connection, causing HTTP request smuggling and request-boundary desynchronization. Commits b78f518478794e16ba3568fc1258e40bf3e8eb3b and 34460b8211d676ef1b9f40d6b775c5e112933690 patch the issue. | |
| Title | uhttpd vulnerable to HTTP request smuggling via invalid chunk-length state reset | |
| Weaknesses | CWE-444 | |
| References |
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| Metrics |
cvssV3_1
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Status: PUBLISHED
Assigner: GitHub_M
Published: 2026-10-30T22:00:19.756Z
Updated: 2026-11-02T18:09:13.455Z
Reserved: 2026-06-16T23:31:22.445Z
Link: CVE-2026-55612
Updated: 2026-11-02T17:03:24.177Z
Status : Deferred
Published: 2026-10-30T22:16:54.950
Modified: 2026-11-02T19:35:33.347
Link: CVE-2026-55612
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