Description
A request smuggling vulnerability exists in libsoup's HTTP/1 header parsing logic. The soup_message_headers_append_common() function in libsoup/soup-message-headers.c unconditionally appends each header value without validating for duplicate or conflicting Content-Length fields. This allows an attacker to send HTTP requests containing multiple Content-Length headers with differing values.
Problem types
Inconsistent Interpretation of HTTP Requests ('HTTP Request/Response Smuggling')
Product status
Timeline
| 2026-02-18: | Reported to Red Hat. |
| 2026-02-18: | Made public. |
Credits
Red Hat would like to thank Cavid for reporting this issue.
References
access.redhat.com/security/cve/CVE-2026-2708
bugzilla.redhat.com/show_bug.cgi?id=2440743 (RHBZ#2440743)
gitlab.gnome.org/GNOME/libsoup/-/issues/500
gitlab.gnome.org/GNOME/libsoup/-/merge_requests/513