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.

The remote Fedora 44 host has a package installed that is affected by multiple vulnerabilities as referenced in the FEDORA-2026-efbe094630 advisory.

    Backport upstream fixes for CVE-2026-54387 and CVE-2026-54388.


Tenable has extracted the preceding description block directly from the Fedora security advisory.

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.

The remote Fedora 43 host has a package installed that is affected by multiple vulnerabilities as referenced in the FEDORA-2026-77f1ca9c8f advisory.

    Backport upstream fixes for CVE-2026-54387 and CVE-2026-54388.


Tenable has extracted the preceding description block directly from the Fedora security advisory.

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.

The Linux/Unix host has one or more packages installed that are impacted by a vulnerability without a vendor supplied patch available.

  - 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. (CVE-2026-54387)

Note that Nessus relies on the presence of the package as reported by the vendor.

ID	Name	Product	Family	Severity
323140	Fedora 44 : tinyproxy (2026-efbe094630)	Nessus	Fedora Local Security Checks	critical
323127	Fedora 43 : tinyproxy (2026-77f1ca9c8f)	Nessus	Fedora Local Security Checks	critical
321742	Linux Distros Unpatched Vulnerability : CVE-2026-54387	Nessus	Misc.	critical

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CVE-2026-54387

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