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Vulnerability · Published Jul 28, 2026 · Assigned by VulnCheck

CVE-2026-66752tiny-http 0.12.0 HTTP Request Smuggling via Transfer-Encoding Handling

Medium 5.4

In plain English

A medium-severity security flaw in tiny-http from tiny-http. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.3% (higher than 26% of all known vulnerabilities). Ready-made attack tooling exists: public proof-of-concept code.

Severity (CVSS 3.1)5.4Medium
Exploit odds (30 days)0.3%top 73.9% of all CVEs
Exploited in the wildNo reportsCISA SSVC: poc
Attack tooling1Public PoC

Official description

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.

Affected packages & fixed versions

EcosystemPackageFixed inAdvisory
Debian:12rust-tiny-httpno fix listedDEBIAN-CVE-2026-66752
Debian:13rust-tiny-httpno fix listedDEBIAN-CVE-2026-66752
Debian:14rust-tiny-httpno fix listedDEBIAN-CVE-2026-66752
Ubuntu:24.04:LTSrust-tiny-httpno fix listedUBUNTU-CVE-2026-66752
Ubuntu:26.04:LTSrust-tiny-httpno fix listedUBUNTU-CVE-2026-66752
Ubuntu:26.10rust-tiny-httpno fix listedUBUNTU-CVE-2026-66752

Affected products (as reported)

VendorProductVersions
tiny-http tiny-http 0 – through 0.12.0

Weakness: CWE-444 · Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:L/I:L/A:N

References