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CVE-2026-54388

Tinyproxy - HTTP Request Smuggling via Duplicate Content-Length Headers

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 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.

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
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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.
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Attack Graph

Products CVE Techniques Tactics

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MITRE ATT&CK

1 technique
Collection
View detailed technique mapping

References

https://github.com/tinyproxy/tinyproxy/commit/364cdb67e0ea00a8e4a7037e2693e0711e816adb
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

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