CVE-2026-103399: Inconsistent Interpretation of HTTP Requests ('HTTP Request/Response Smuggling') in Red Hat Red Hat Enterprise Linux 10
A flaw was found in SoupServer (libsoup). When an HTTP/1.x client sends a request with Expect: 100-continue and a request body, and SoupServer returns an early final (non-1xx) response before the body is read, the server neither drains the declared body bytes nor closes the connection. On a keep-alive connection, those leftover bytes are interpreted as a subsequent HTTP request. A remote, unauthenticated attacker can place a complete HTTP request in the body and cause SoupServer to process that smuggled request, leading to unintended request handling.
CVE-2026-103399: Inconsistent Interpretation of HTTP Requests ('HTTP Request/Response Smuggling') in Red Hat Red Hat Enterprise Linux 10
Description
A flaw was found in SoupServer (libsoup). When an HTTP/1.x client sends a request with Expect: 100-continue and a request body, and SoupServer returns an early final (non-1xx) response before the body is read, the server neither drains the declared body bytes nor closes the connection. On a keep-alive connection, those leftover bytes are interpreted as a subsequent HTTP request. A remote, unauthenticated attacker can place a complete HTTP request in the body and cause SoupServer to process that smuggled request, leading to unintended request handling.
CVSS v3.1
Score 5.3medium
Affected software
Red Hat
Red Hat Enterprise Linux 10
Red Hat
Red Hat Enterprise Linux 6
Red Hat
Red Hat Enterprise Linux 7
Red Hat
Red Hat Enterprise Linux 8
Red Hat
Red Hat Enterprise Linux 9
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- redhat
- Date Reserved
- 2026-09-30T14:31:37.532Z
- Cvss Version
- 3.1
- State
- PUBLISHED
- Vendor Advisory Urls
- [{"url":"https://access.redhat.com/security/cve/CVE-2026-103399","vendor":"Red Hat"}]
Threat ID: 6abd4b862a4e24523d52ada2
Added to database: 09/30/2026, 17:48:54 UTC
Last updated: 09/30/2026, 17:48:54 UTC
Views: 1
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