Vulnerability · Published Mar 17, 2026 · Assigned by redhat
CVE-2026-3632Libsoup: libsoup: http smuggling and server-side request forgery via malformed hostnames
Low 3.9
In plain English
A low-severity security flaw in Red Hat Enterprise Linux 10 from Red Hat. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.2% (higher than 13% of all known vulnerabilities).
Official description
A flaw was found in libsoup, a library used by applications to send network requests. This vulnerability occurs because libsoup does not properly validate hostnames, allowing special characters to be injected into HTTP headers. A remote attacker could exploit this to perform HTTP smuggling, where they can send hidden, malicious requests alongside legitimate ones. In certain situations, this could lead to Server-Side Request Forgery (SSRF), enabling an attacker to force the server to make unauthorized requests to other internal or external systems. The impact is low, as SoupServer is not actually used in internet infrastructure.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian:14 | libsoup | no fix listed | DEBIAN-CVE-2026-3632 |
| Debian:12 | libsoup2.4 | no fix listed | DEBIAN-CVE-2026-3632 |
| Debian:13 | libsoup2.4 | no fix listed | DEBIAN-CVE-2026-3632 |
| Debian:12 | libsoup3 | no fix listed | DEBIAN-CVE-2026-3632 |
| Debian:13 | libsoup3 | no fix listed | DEBIAN-CVE-2026-3632 |
| Ubuntu:22.04:LTS | libsoup2.4 | no fix listed | UBUNTU-CVE-2026-3632 |
| Ubuntu:24.04:LTS | libsoup2.4 | no fix listed | UBUNTU-CVE-2026-3632 |
| Ubuntu:25.10 | libsoup2.4 | no fix listed | UBUNTU-CVE-2026-3632 |
| Ubuntu:26.10 | libsoup2.4 | no fix listed | UBUNTU-CVE-2026-3632 |
| Ubuntu:24.04:LTS | libsoup3 | no fix listed | UBUNTU-CVE-2026-3632 |
| Ubuntu:25.10 | libsoup3 | no fix listed | UBUNTU-CVE-2026-3632 |
| Ubuntu:26.04:LTS | libsoup3 | no fix listed | UBUNTU-CVE-2026-3632 |
| Ubuntu:26.10 | libsoup3 | no fix listed | UBUNTU-CVE-2026-3632 |
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| Red Hat | Red Hat Enterprise Linux 10 | see references |
| Red Hat | Red Hat Enterprise Linux 6 | see references |
| Red Hat | Red Hat Enterprise Linux 7 | see references |
| Red Hat | Red Hat Enterprise Linux 8 | see references |
| Red Hat | Red Hat Enterprise Linux 9 | see references |
Weakness: CWE-1286 · Vector: CVSS:3.1/AV:N/AC:H/PR:H/UI:R/S:U/C:L/I:L/A:L
References
- https://access.redhat.com/security/cve/CVE-2026-3632 vdb-entry, x_refsource_REDHAT
- RHBZ#2445127 issue-tracking, x_refsource_REDHAT
- https://gitlab.gnome.org/GNOME/libsoup/-/issues/483