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CVE

CVE-2026-54388

Tinyproxy - HTTP Request Smuggling via Duplicate Content-Length Headers
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CVE

CVE-2026-54388

Tinyproxy - HTTP Request Smuggling via Duplicate Content-Length Headers

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.

Package Versions Affected

Package Version
patch Availability
No items found.

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CVSS Version

Severity
Base Score
CVSS Version
Score Vector
C
H
U
9.3
-
4.0
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
C
H
U
0
-
C
H
U
-

Related Resources

No items found.

References

https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/54xxx/CVE-2026-54388.json, https://nvd.nist.gov/vuln/detail/CVE-2026-54388, https://www.vulncheck.com/advisories/tinyproxy-http-request-smuggling-via-duplicate-content-length-headers, https://github.com/tinyproxy/tinyproxy/issues/609, https://github.com/tinyproxy/tinyproxy/pull/610, https://github.com/tinyproxy/tinyproxy/commit/364cdb67e0ea00a8e4a7037e2693e0711e816adb, https://github.com/tinyproxy/tinyproxy

Severity

0

CVSS Score
0
10

Basic Information

Base CVSS
0
EPSS Probability
0.00439%
EPSS Percentile
0.35636%
Introduced Version
0
Fix Available
364cdb67e0ea00a8e4a7037e2693e0711e816adb

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