UBUNTU-CVE-2026-54283 (CVE-2026-54283)

Vulnerability from osv_ubuntu – Published: 2026-06-22 18:16 – Updated: 2026-06-24 09:03 – Source website
VLAI
Details

Starlette is a lightweight ASGI framework/toolkit. From 0.4.1 until 1.3.1, request.form() accepts max_fields and max_part_size to bound resource consumption while parsing form data. These limits are enforced for multipart/form-data, but silently ignored for application/x-www-form-urlencoded. An unauthenticated attacker can therefore send a urlencoded body with an arbitrarily large number of fields or an arbitrarily large field, even when the application configured limits it believed would apply. This vulnerability is fixed in 1.3.1.

Severity
7.5 (High)
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
N/A (UNKNOWN)
medium
References
To clipboard 

{
  "affected": [
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "python3-starlette",
            "binary_version": "0.18.0-1"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:22.04:LTS",
        "name": "starlette",
        "purl": "pkg:deb/ubuntu/starlette@0.18.0-1?arch=source\u0026distro=jammy"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "0.14.1-1",
        "0.16.0-1",
        "0.18.0-1"
      ]
    },
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "python3-starlette",
            "binary_version": "0.31.1-1"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:24.04:LTS",
        "name": "starlette",
        "purl": "pkg:deb/ubuntu/starlette@0.31.1-1?arch=source\u0026distro=noble"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "0.30.0-1",
        "0.31.1-1"
      ]
    },
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "python3-starlette",
            "binary_version": "0.46.1-3"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:25.10",
        "name": "starlette",
        "purl": "pkg:deb/ubuntu/starlette@0.46.1-3?arch=source\u0026distro=questing"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "0.46.1-2",
        "0.46.1-3"
      ]
    },
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "python3-starlette",
            "binary_version": "0.50.0-1"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:26.04:LTS",
        "name": "starlette",
        "purl": "pkg:deb/ubuntu/starlette@0.50.0-1?arch=source\u0026distro=resolute"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "0.46.1-3",
        "0.50.0-1"
      ]
    }
  ],
  "aliases": [],
  "details": "Starlette is a lightweight ASGI framework/toolkit. From 0.4.1 until 1.3.1, request.form() accepts max_fields and max_part_size to bound resource consumption while parsing form data. These limits are enforced for multipart/form-data, but silently ignored for application/x-www-form-urlencoded. An unauthenticated attacker can therefore send a urlencoded body with an arbitrarily large number of fields or an arbitrarily large field, even when the application configured limits it believed would apply. This vulnerability is fixed in 1.3.1.",
  "id": "UBUNTU-CVE-2026-54283",
  "modified": "2026-06-24T09:03:12Z",
  "published": "2026-06-22T18:16:00Z",
  "references": [
    {
      "type": "REPORT",
      "url": "https://ubuntu.com/security/CVE-2026-54283"
    },
    {
      "type": "REPORT",
      "url": "https://www.cve.org/CVERecord?id=CVE-2026-54283"
    },
    {
      "type": "REPORT",
      "url": "https://github.com/Kludex/starlette/security/advisories/GHSA-82w8-qh3p-5jfq"
    },
    {
      "type": "REPORT",
      "url": "https://github.com/Kludex/starlette/pull/3329"
    }
  ],
  "related": [],
  "schema_version": "1.7.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
      "type": "CVSS_V3"
    },
    {
      "score": "medium",
      "type": "Ubuntu"
    }
  ],
  "upstream": [
    "CVE-2026-54283"
  ]
}



Log in or create an account to share your comment.




Tags
Taxonomy of the tags.





Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.

Sightings

Author Source Type Date Other

Nomenclature

  • Seen: The vulnerability was mentioned, discussed, or observed by the user.
  • Confirmed: The vulnerability has been validated from an analyst's perspective.
  • Published Proof of Concept: A public proof of concept is available for this vulnerability.
  • Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
  • Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
  • Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
  • Not confirmed: The user expressed doubt about the validity of the vulnerability.
  • Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.



Related by attack behaviour

Vulnerabilities whose description is nearest to this one in the vector space of the CIRCL/vulnerability-attack-technique-biencoder model. This is a similarity search over the bi-encoder space (plain cosine), not a classification, and it has no measured accuracy.