GNOME libsoup Chunked soup_filter_input_stream_read_line request smuggling

Summaryinfo

A vulnerability identified as problematic has been detected in GNOME libsoup. Affected by this vulnerability is the function soup_filter_input_stream_read_line of the component Chunked Handler. Performing a manipulation results in request smuggling. This vulnerability is reported as CVE-2026-1801. The attack is possible to be carried out remotely. No exploit exists.

Detailsinfo

A vulnerability was found in GNOME libsoup (affected version not known). It has been classified as problematic. This affects the function soup_filter_input_stream_read_line of the component Chunked Handler. The manipulation with an unknown input leads to a request smuggling vulnerability. CWE is classifying the issue as CWE-444. The product acts as an intermediary HTTP agent (such as a proxy or firewall) in the data flow between two entities such as a client and server, but it does not interpret malformed HTTP requests or responses in ways that are consistent with how the messages will be processed by those entities that are at the ultimate destination. This is going to have an impact on integrity. The summary by CVE is:

A flaw was found in libsoup, an HTTP client/server library. This HTTP Request Smuggling vulnerability arises from non-RFC-compliant parsing in the soup_filter_input_stream_read_line() logic, where libsoup accepts malformed chunk headers, such as lone line feed (LF) characters instead of the required carriage return and line feed (CRLF). A remote attacker can exploit this without authentication or user interaction by sending specially crafted chunked requests. This allows libsoup to parse and process multiple HTTP requests from a single network message, potentially leading to information disclosure.

The advisory is shared at access.redhat.com. This vulnerability is uniquely identified as CVE-2026-1801 since 02/03/2026. The exploitability is told to be easy. It is possible to initiate the attack remotely. No form of authentication is needed for exploitation. Technical details are known, but no exploit is available. The price for an exploit might be around USD $0-$5k at the moment (estimation calculated on 03/26/2026).

The vulnerability scanner Nessus provides a plugin with the ID 297750 (Linux Distros Unpatched Vulnerability : CVE-2026-1801), which helps to determine the existence of the flaw in a target environment.

There is no information about possible countermeasures known. It may be suggested to replace the affected object with an alternative product.

The vulnerability is also documented in the vulnerability database at Tenable (297750). If you want to get the best quality for vulnerability data then you always have to consider VulDB.

Productinfo

Vendor

• GNOME

Name

• libsoup

License

• open-source

Website

• Vendor: https://www.gnome.org/

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If you want to get the best quality for vulnerability data then you always have to consider VulDB.

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