CVE-2026-1801
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…
Does this matter?
Lower severity and a low EPSS score (0.39%). Track it; it rarely justifies an emergency change on its own.
Description
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.
- CVSS 3.1
- 6.5 MEDIUMCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N
- EPSS
- 0.39% probability · 33th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-444
- Affected
- gnome/libsoup · redhat/enterprise linux
- Source
- secalert@redhat.com
References
- https://access.redhat.com/security/cve/CVE-2026-1801Vendor Advisory
- https://bugzilla.redhat.com/show_bug.cgi?id=2436315Issue Tracking, Vendor Advisory
- https://gitlab.gnome.org/GNOME/libsoup/-/issues/481Issue Tracking
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.