CVE-2026-2708
Libsoup: libsoup: http request smuggling via duplicate content-length headers
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.
INFO
Published Date :
April 23, 2026, 10:16 p.m.
Last Modified :
May 4, 2026, 6:28 p.m.
Remotely Exploit :
Yes !
Source :
[email protected]
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS 3.1 | LOW | 53f830b8-0a3f-465b-8143-3b8a9948e749 | ||||
| CVSS 3.1 | LOW | [email protected] | ||||
| CVSS 3.1 | LOW | MITRE-CVE | ||||
| CVSS 3.1 | MEDIUM | [email protected] |
Solution
- Update libsoup to a version that validates Content-Length headers.
- Ensure Content-Length headers are unique and consistent.
- Implement strict validation for HTTP/1 header parsing.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-2708.
| URL | Resource |
|---|---|
| https://access.redhat.com/security/cve/CVE-2026-2708 | Vendor Advisory |
| https://bugzilla.redhat.com/show_bug.cgi?id=2440743 | Issue Tracking Vendor Advisory |
| https://gitlab.gnome.org/GNOME/libsoup/-/issues/500 | Exploit Issue Tracking Vendor Advisory |
| https://gitlab.gnome.org/GNOME/libsoup/-/merge_requests/513 | Issue Tracking |
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-2708 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-2708
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-2708 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-2708 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
Initial Analysis by [email protected]
May. 04, 2026
Action Type Old Value New Value Added CVSS V3.1 AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N Added CPE Configuration OR *cpe:2.3:o:redhat:enterprise_linux:7.0:*:*:*:*:*:*:* *cpe:2.3:o:redhat:enterprise_linux:6.0:*:*:*:*:*:*:* *cpe:2.3:o:redhat:enterprise_linux:8.0:*:*:*:*:*:*:* *cpe:2.3:o:redhat:enterprise_linux:9.0:*:*:*:*:*:*:* *cpe:2.3:o:redhat:enterprise_linux:10.0:*:*:*:*:*:*:* *cpe:2.3:a:gnome:libsoup:-:*:*:*:*:*:*:* Added Reference Type Red Hat, Inc.: https://access.redhat.com/security/cve/CVE-2026-2708 Types: Vendor Advisory Added Reference Type Red Hat, Inc.: https://bugzilla.redhat.com/show_bug.cgi?id=2440743 Types: Issue Tracking, Vendor Advisory Added Reference Type Red Hat, Inc.: https://gitlab.gnome.org/GNOME/libsoup/-/issues/500 Types: Exploit, Issue Tracking, Vendor Advisory Added Reference Type Red Hat, Inc.: https://gitlab.gnome.org/GNOME/libsoup/-/merge_requests/513 Types: Issue Tracking -
New CVE Received by [email protected]
Apr. 23, 2026
Action Type Old Value New Value Added 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. Added CVSS V3.1 AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:N Added CWE CWE-444 Added Reference https://access.redhat.com/security/cve/CVE-2026-2708 Added Reference https://bugzilla.redhat.com/show_bug.cgi?id=2440743 Added Reference https://gitlab.gnome.org/GNOME/libsoup/-/issues/500 Added Reference https://gitlab.gnome.org/GNOME/libsoup/-/merge_requests/513