CVE-2026-1801Medium· 5.3▾ TwilightPoC availableA 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,…
▾ Twilight zone — High severity, or a signal on a lesser flaw
impact 29.2 · likelihood 0.1 · exploitation 12
A public proof-of-concept already exists for this vulnerability — see Exploit availability below.
Public exploit / PoC code seen in 1 source. Availability, not in-the-wild use.
Stakeholder-Specific Vulnerability Categorization from CISA's ADP record at CVE.org: whether exploitation is observed, whether an attack can be automated, and how much of the system is at stake. The CVSS score shown above comes from the assigning CNA record, not NVD.
Exploit-prediction probability, daily snapshots since Nov 6.
Disclosure to exploitation, from the record and what we observed since indexing it.
Disclosed via CVEORG
Last analysed / modified upstream
0.4%
1 GitHub repo (last check)
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.
libsoup3 (all versions)libsoup (all versions)libsoup (all versions)libsoup (all versions)libsoup (all versions)Refer to the linked advisories for vendor-supplied fixes and affected version ranges.
Mitigation for this issue is either not available or the currently available options don't meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base or stability.
Connected by shared product, vendor, weakness, or advisory.
CVE-2026-6324Medium· 4.8Libsoup: libsoup: http request smuggling via unsigned to signed conversion error
CVE-2026-66338Medium· 5.4Libsoup: libsoup: http request smuggling via permissive chunk-size parsing in soup_body_input_stream_read_chunked()
CVE-2026-2708Low· 3.7Libsoup: libsoup: http request smuggling via duplicate content-length headers
CVE-2026-1760Medium· 5.3Libsoup: soupserver: denial of service via http request smuggling
CVE-2026-103399Medium· 5.3A flaw was found in SoupServer (libsoup)
CVE-2025-14523High· 8.2A flaw in libsoup’s HTTP header handling allows multiple Host: headers in a request and returns the last occurrence for server-side processing