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40Track*

Tinyproxy - HTTP Request Smuggling via Duplicate Content-Length Headers

tinyproxy · CVE-2026-54388
0 news outlets0 CERTs and agencies0 research labs

Assessment: Track*

SSVC decision points: exploitation poc, automatable yes, technical impact total, deployment low.

What is it?

Tinyproxy through 1.11.3, fixed in commit 364cdb6, fails to reject requests containing multiple Content-Length headers with differing values, forwarding all duplicate headers to the backend while using the first value to determine how many request body bytes to consume. Remote attackers can desynchronize the proxy and backend parser state, allowing injection of arbitrary HTTP requests to the backend to enable cache poisoning, access control bypass, and request hijacking.

Evidence

No coverage recorded yet.

Exploitation

  • Exploit code published (not verified by us)
  • Exploited in the wild (confirmed by a source)
  • Listed as known exploited (CISA KEV)
CVSS
9.1
EPSS
–
First seen
17 Jun 2026
Status
corroborated

All tinyproxy vulnerabilities