CVE Tools
Sign in

CVE-2026-54387

Tinyproxy - HTTP Request Smuggling via CL/TE Desynchronization

Published: Jun 17, 2026Updated: Jul 14, 2026 Sources: CVE List NVDCWE-444
9.1CRITICAL
NVD MITRE
EPSS Score
0.4%
Top 64.2%
CISA KEV
Not in KEV
Exploits
No Known Exploits
Remediation
No Fix Available
Self-Check
OpenVAS

Description

Tinyproxy through 1.11.3, fixed in commit ff45d3b, fails to reconcile conflicting Content-Length and Transfer-Encoding: chunked headers, forwarding both verbatim to the backend while using Content-Length 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.

No summary for this CVE yet.

CVSS Vector Breakdown

AV:NAC:LPR:NUI:NS:UC:HI:HA:N
Exploitability
AV:NAttack Vector
Network
AC:LAttack Complexity
Low
PR:NPrivileges Required
None
UI:NUser Interaction
None
Scope
S:UScope
Unchanged
Impact
C:HConfidentiality
High
I:HIntegrity
High
A:NAvailability
None
Open in CVSS calculator →

Weaknesses

CWE-444

Affected Products

tinyproxy
oss-projectaka tiny proxy
tinyproxyOn-prem
Networking Infrastructure / load-balancer-proxy

Exploitability

No known exploits, KEV entries, or remediation guidance available for this vulnerability yet.
Is your org exposed to CVE-2026-54387?We can run the check for you — a free external exposure review, no install. Check my exposure

Attack Graph

Products CVE Techniques Tactics

Click technique nodes for MITRE ATT&CK details · drag to pan · Ctrl/⌘ + scroll to zoom, or go fullscreen.

MITRE ATT&CK

1 technique
Collection
View detailed technique mapping

References

https://github.com/tinyproxy/tinyproxy/commit/ff45d3bf0e61d0f8ed97ab379d3047f04eb67521
github.com
https://github.com/tinyproxy/tinyproxy/issues/609
github.com
https://github.com/tinyproxy/tinyproxy/pull/610
github.com
and 1 more references View all →
News mentions
1

Unlock Complete Vulnerability Intelligence

Get the full picture for CVE-2026-54387 and every CVE in our database. Create a free account — no credit card required.

Create Free Account
Plain-language analysis
Impact assessment and exploitation scenario in plain English
Attack graph visualization
Interactive attack path and kill chain mapping
Exploit details & PoC links
ExploitDB, Metasploit, GitHub PoCs with direct links
Nuclei scanner templates
Ready-to-use vulnerability scanner templates
Full remediation guide
Patch instructions, workarounds, and compliance impact
Interactive AI chat
Ask questions about this vulnerability in natural language
Related vulnerabilities
Semantically similar CVEs and attack patterns
REST API & MCP access
Integrate vulnerability data into your workflows