CVE-2026-1760: libsoup2.4 HTTP Request/Response Smuggling

Vulnerability summary

CVE-2026-1760 is a medium (CVSS 5.3) HTTP Request/Response Smuggling vulnerability in libsoup2.4. EPSS estimates a 0.48% chance of exploitation in the next 30 days, higher than 40.3% of scored vulnerabilities.

Timeline

1. 02-02-2026
   PublishedVulnerability first disclosed.
2. 19-03-2026
   Last modifiedVulnerability information updated.

Description

A flaw was found in SoupServer. This HTTP request smuggling vulnerability occurs because SoupServer improperly handles requests that combine Transfer-Encoding: chunked and Connection: keep-alive headers. A remote, unauthenticated client can exploit this by sending specially crafted requests, causing SoupServer to fail to close the connection as required by RFC 9112. This allows the attacker to smuggle additional requests over the persistent connection, leading to unintended request processing and potential denial-of-service (DoS) conditions.

• CWE-444Inconsistent Interpretation of HTTP Requests ('HTTP Request/Response Smuggling')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.