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TI-2026-65685 Aliases CVE-2026-103399GHSA-mfgq-q7gx-p678

Libsoup: soupserver: http/1 request smuggling via undrained expect: 100-continue body

Priority LOW 30CWE-444Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
None
Attack complexity
Low
Impact type
—
Confidentiality · integrity · availability
None · Low · None
Fix status
Deferred Red Hat: fix deferred

Attack profile from CVSS 3.1 · CNA. Fix status from CNA and Red Hat.

Summary

A flaw was found in SoupServer (libsoup). When an HTTP/1.x client sends a request with Expect: 100-continue and a request body, and SoupServer returns an early final (non-1xx) response before the body is read, the server neither drains the declared body bytes nor closes the connection. On a keep-alive connection, those leftover bytes are interpreted as a subsequent HTTP request. A remote, unauthenticated attacker can place a complete HTTP request in the body and cause SoupServer to process that smuggled request, leading to unintended request handling.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00246 15th percentileScored 2026-11-07
Fix Deferred Red Hat: fix deferred

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
None
Automatable
Yes
Technical impact
Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
Red HatRed Hat Enterprise Linux 10——No fix listedCNA
Red HatRed Hat Enterprise Linux 6——No fix listedCNA
Red HatRed Hat Enterprise Linux 7——No fix listedCNA
Red HatRed Hat Enterprise Linux 8——No fix listedCNA
Red HatRed Hat Enterprise Linux 9——No fix listedCNA
  • Red Hat Enterprise Linux 10 VendorRed Hat Affected — Fixed in — No fix listed CNA
  • Red Hat Enterprise Linux 6 VendorRed Hat Affected — Fixed in — No fix listed CNA
  • Red Hat Enterprise Linux 7 VendorRed Hat Affected — Fixed in — No fix listed CNA
  • Red Hat Enterprise Linux 8 VendorRed Hat Affected — Fixed in — No fix listed CNA
  • Red Hat Enterprise Linux 9 VendorRed Hat Affected — Fixed in — No fix listed CNA

CPE names CNA · 5

CPEVersionsRoleVendor
cpe:/a:redhat:enterprise_linux:1010—Red Hat
cpe:/o:redhat:rhel_els:66—Red Hat
cpe:/o:redhat:rhel_els:77—Red Hat
cpe:/a:redhat:enterprise_linux:88—Red Hat
cpe:/a:redhat:enterprise_linux:99—Red Hat
  • cpe:/a:redhat:enterprise_linux:10 Versions 10 — ·Red Hat
  • cpe:/o:redhat:rhel_els:6 Versions 6 — ·Red Hat
  • cpe:/o:redhat:rhel_els:7 Versions 7 — ·Red Hat
  • cpe:/a:redhat:enterprise_linux:8 Versions 8 — ·Red Hat
  • cpe:/a:redhat:enterprise_linux:9 Versions 9 — ·Red Hat

Remediation

No fixed version listed by the sources yet.

Vendor assessments

Red Hat

Red Hat rating: Moderate. Red Hat's page for this CVE →

ProductStatusPlan or fix
Red Hat Enterprise Linux 10AffectedNo fix yet: Fix deferred
Red Hat Enterprise Linux 6AffectedNo fix planned: Out of support scope
Red Hat Enterprise Linux 7AffectedNo fix yet: Fix deferred
Red Hat Enterprise Linux 8AffectedNo fix yet: Fix deferred
Red Hat Enterprise Linux 9AffectedNo fix yet: Fix deferred

Timeline

  1. 2026-10-02 Threatist record created from CVE-2026-103399
  2. 2026-10-03 Alias added: GHSA-mfgq-q7gx-p678

References

Other 2

  • TI-2019-15875 Protection mechanism failure in Jenkins Pipeline: Groovy Plugin KEVCVSS 3.1CRITICAL 9.9
  • TI-2019-15874 Protection mechanism failure in Jenkins Script Security Plugin KEVCVSS 3.1CRITICAL 9.9
  • TI-2019-08259 Underflow in PHP-FPM can lead to RCE KEVCVSS 3.1CRITICAL 9.8
  • TI-2019-05363 Code injection in Elastic Kibana KEVCVSS 3.1CRITICAL 10.0
  • TI-2019-03949 Out-of-bounds write in ESXi and Horizon DaaS KEVCVSS 3.1CRITICAL 9.8
  • TI-2018-16080 A code execution vulnerability exists in the Stapler web framework used by Jenkins 2.153… KEVCVSS 3.1CRITICAL 9.8
See all 7412 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences