CVE-2026-66752CWE-444

tiny-http 0.12.0 HTTP Request Smuggling via Transfer-Encoding Handling

Medium · published July 28, 2026

CVSS v4.0
6.3
EPSS
0%
Percentile
24.7
In the wild
Unconfirmed
What it is

tiny-http through 0.12.0 contains an HTTP request smuggling vulnerability that allows remote attackers to desynchronize request framing by sending a Transfer-Encoding header with any value, including non-chunked codings, which causes the library to unconditionally apply chunk-decoding and discard Content-Length. Attackers can exploit the discrepancy between tiny_http's improper Transfer-Encoding parsing and a correctly-implemented front-end proxy to produce two distinct interpretations of a single byte stream, enabling request smuggling, and can additionally send non-chunked bodies with non-chunked Transfer-Encoding values to cause failed body reads that tie up connections and consume worker threads without signaling errors to clients.

The record
Technical detail
CVSS v4.0
6.3 · MEDIUM
Vector
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:L/VA:L/SC:N/SI:L/SA:L
EPSS
0.00329 · 24.7th percentile
Weakness
CWE-444 · Inconsistent Interpretation of HTTP Requests ('HTTP Request/Response Smuggling')
Published
2026-07-28T15:44Z
EPSS history
Timeline
  • 28 JUL 15:44Z
    tiny-http 0.12.0 HTTP Request Smuggling via Transfer-Encoding Handling
    cvelistv5