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

Type: advisorySource: Official CVE List1 source record

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.

Announced Source revision 1
Original source ↗

CVE-2026-103399

Primary source · Revision 1

Imported from structured advisory data. Source references identify upstream records or fields; verify affected versions and your deployed configuration.

Security context

Source reference: cve:CVE-2026-103399

Red Hat Enterprise Linux 10

Source reference: /containers/cna/affected/0/product

Affected versions
Not stated in this record
Fixed versions
Not stated in this record
Prerequisites
Not stated in this record

Red Hat Enterprise Linux 6

Source reference: /containers/cna/affected/1/product

Affected versions
Not stated in this record
Fixed versions
Not stated in this record
Prerequisites
Not stated in this record

Red Hat Enterprise Linux 7

Source reference: /containers/cna/affected/2/product

Affected versions
Not stated in this record
Fixed versions
Not stated in this record
Prerequisites
Not stated in this record

Red Hat Enterprise Linux 8

Source reference: /containers/cna/affected/3/product

Affected versions
Not stated in this record
Fixed versions
Not stated in this record
Prerequisites
Not stated in this record

Red Hat Enterprise Linux 9

Source reference: /containers/cna/affected/4/product

Affected versions
Not stated in this record
Fixed versions
Not stated in this record
Prerequisites
Not stated in this record

Structured affected-version data

Original package identities and version rules from this source.

[
  {
    "cpes": [
      "cpe:/o:redhat:enterprise_linux:10"
    ],
    "vendor": "Red Hat",
    "product": "Red Hat Enterprise Linux 10",
    "packageName": "libsoup3",
    "collectionURL": "https://access.redhat.com/downloads/content/package-browser/",
    "defaultStatus": "affected"
  },
  {
    "cpes": [
      "cpe:/o:redhat:enterprise_linux:6"
    ],
    "vendor": "Red Hat",
    "product": "Red Hat Enterprise Linux 6",
    "packageName": "libsoup",
    "collectionURL": "https://access.redhat.com/downloads/content/package-browser/",
    "defaultStatus": "unknown"
  },
  {
    "cpes": [
      "cpe:/o:redhat:enterprise_linux:7"
    ],
    "vendor": "Red Hat",
    "product": "Red Hat Enterprise Linux 7",
    "packageName": "libsoup",
    "collectionURL": "https://access.redhat.com/downloads/content/package-browser/",
    "defaultStatus": "affected"
  },
  {
    "cpes": [
      "cpe:/o:redhat:enterprise_linux:8"
    ],
    "vendor": "Red Hat",
    "product": "Red Hat Enterprise Linux 8",
    "packageName": "libsoup",
    "collectionURL": "https://access.redhat.com/downloads/content/package-browser/",
    "defaultStatus": "affected"
  },
  {
    "cpes": [
      "cpe:/o:redhat:enterprise_linux:9"
    ],
    "vendor": "Red Hat",
    "product": "Red Hat Enterprise Linux 9",
    "packageName": "libsoup",
    "collectionURL": "https://access.redhat.com/downloads/content/package-browser/",
    "defaultStatus": "affected"
  }
]
Related CVEs
CVE-2026-103399

Source reference: /cveMetadata/cveId

Publisher severity

medium

Source reference: /containers/cna/metrics

Event
#4823 · Revision 1
Added to Heist Feed
Publisher date
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