Medium severity · published Feb 3, 2026
CVE-2026-1801
A flaw was found in libsoup, an HTTP client/server library
6.5
CVSS
0.4%
EPSS
No
On KEV
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 vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Confidentiality
Low
Integrity
Low
Availability
None
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.4% · higher than 37% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
EL
Enterprise Linux · Redhat
6.0; 7.0; 8.0; 9.0; 10.0 · source: NVD
LI
Libsoup · Gnome
All versions, or not specified · source: NVD
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-1801
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-1801
Vendor Advisory
https://access.redhat.com/security/cve/CVE-2026-1801
Issue Tracking
https://bugzilla.redhat.com/show_bug.cgi?id=2436315
Issue Tracking
https://gitlab.gnome.org/GNOME/libsoup/-/issues/481
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