CVE-2026-3632Libsoup: libsoup: http smuggling and server-side request forgery via malformed hostnames
- 3.9LowCVSS base score
- 0.25%Exploitation in 30 daysEPSS · top 84% of all CVEs
- NoKnown exploitednot in CISA's KEV catalog
- NonePublic exploitsnone known yet
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.
Timeline
ID reserved
By redhat
- 11 days later
· 11 days later
Published
- 8 months later
· 8 months later
Record updated
Changes after publication (a new score, a public exploit, EPSS crossing 1, 10 or 50 %, leaving KEV) are kept since November 2026; earlier ones are not known.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| redhatCNA (assigner) | 3.1 | Low3.9 | CVSS:3.1/AV:N/AC:H/PR:H/UI:R/S:U/C:L/I:L/A:L |
| NVDNVD · Analyzed | 3.1 | Medium5.5 | CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:L/I:L/A:L |
- EPSS (exploitation in 30 days)
- 0.25% · top 84% of all CVEs (14 Nov 2026)
- CISA SSVC
- Exploitation: none · Automatable: no · Technical impact: partial
The list uses the assigner's score when there is one, then CISA's, then NVD's: Low 3.9.
Affected products
Red Hat · Red Hat Enterprise Linux 10
All versions: affected
Red Hat · Red Hat Enterprise Linux 6
All versions: unknown
Red Hat · Red Hat Enterprise Linux 7
All versions: affected
Red Hat · Red Hat Enterprise Linux 8
All versions: affected
Red Hat · Red Hat Enterprise Linux 9
All versions: affected
What to do
Workaround: Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base or stability.
References
References3
- https://access.redhat.com/security/cve/CVE-2026-3632 (opens in a new tab)vdb-entryx_refsource_REDHAT
- RHBZ#2445127 (opens in a new tab)issue-trackingx_refsource_REDHAT
- https://gitlab.gnome.org/GNOME/libsoup/-/issues/483 (opens in a new tab)
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- EUVD EUVD-2026-12559 (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisories (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://cveledger.app/cve/CVE-2026-3632)Record last updated .