CVE-2026-54283 (GCVE-0-2026-54283)

Vulnerability from cvelistv5 – Published: 2026-06-22 16:46 – Updated: 2026-06-23 16:10
VLAI
Title
Starlette: request.form() limits silently ignored for application/x-www-form-urlencoded enable DoS
Summary
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
SSVC
Exploitation: none Automatable: yes Technical Impact: partial
CISA Coordinator (v2.0.3)
CWE
  • CWE-770 - Allocation of Resources Without Limits or Throttling
Assigner
References
Impacted products
Vendor Product Version
Kludex starlette Affected: >= 0.4.1, < 1.3.1
Create a notification for this product.
Show details on NVD website
To clipboard 

{
  "containers": {
    "adp": [
      {
        "metrics": [
          {
            "other": {
              "content": {
                "id": "CVE-2026-54283",
                "options": [
                  {
                    "Exploitation": "none"
                  },
                  {
                    "Automatable": "yes"
                  },
                  {
                    "Technical Impact": "partial"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-06-23T16:06:30.546768Z",
                "version": "2.0.3"
              },
              "type": "ssvc"
            }
          }
        ],
        "providerMetadata": {
          "dateUpdated": "2026-06-23T16:10:51.227Z",
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
        },
        "title": "CISA ADP Vulnrichment"
      }
    ],
    "cna": {
      "affected": [
        {
          "product": "starlette",
          "vendor": "Kludex",
          "versions": [
            {
              "status": "affected",
              "version": "\u003e= 0.4.1, \u003c 1.3.1"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "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."
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "attackComplexity": "LOW",
            "attackVector": "NETWORK",
            "availabilityImpact": "HIGH",
            "baseScore": 7.5,
            "baseSeverity": "HIGH",
            "confidentialityImpact": "NONE",
            "integrityImpact": "NONE",
            "privilegesRequired": "NONE",
            "scope": "UNCHANGED",
            "userInteraction": "NONE",
            "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
            "version": "3.1"
          }
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-770",
              "description": "CWE-770: Allocation of Resources Without Limits or Throttling",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-06-22T16:46:16.706Z",
        "orgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
        "shortName": "GitHub_M"
      },
      "references": [
        {
          "name": "https://github.com/Kludex/starlette/security/advisories/GHSA-82w8-qh3p-5jfq",
          "tags": [
            "x_refsource_CONFIRM"
          ],
          "url": "https://github.com/Kludex/starlette/security/advisories/GHSA-82w8-qh3p-5jfq"
        }
      ],
      "source": {
        "advisory": "GHSA-82w8-qh3p-5jfq",
        "discovery": "UNKNOWN"
      },
      "title": "Starlette: request.form() limits silently ignored for application/x-www-form-urlencoded enable DoS"
    }
  },
  "cveMetadata": {
    "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
    "assignerShortName": "GitHub_M",
    "cveId": "CVE-2026-54283",
    "datePublished": "2026-06-22T16:46:16.706Z",
    "dateReserved": "2026-06-12T17:46:37.292Z",
    "dateUpdated": "2026-06-23T16:10:51.227Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2",
  "vulnerability-lookup:meta": {
    "epss": {
      "cve": "CVE-2026-54283",
      "date": "2026-07-26",
      "epss": "0.00397",
      "percentile": "0.32399"
    },
    "nvd": "{\"cve\":{\"id\":\"CVE-2026-54283\",\"sourceIdentifier\":\"security-advisories@github.com\",\"published\":\"2026-06-22T18:16:46.943\",\"lastModified\":\"2026-06-26T19:16:55.750\",\"vulnStatus\":\"Analyzed\",\"cveTags\":[],\"descriptions\":[{\"lang\":\"en\",\"value\":\"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.\"}],\"affected\":[{\"source\":\"security-advisories@github.com\",\"affectedData\":[{\"vendor\":\"Kludex\",\"product\":\"starlette\",\"versions\":[{\"version\":\"\u003e= 0.4.1, \u003c 1.3.1\",\"status\":\"affected\"}]}]}],\"metrics\":{\"cvssMetricV31\":[{\"source\":\"security-advisories@github.com\",\"type\":\"Secondary\",\"cvssData\":{\"version\":\"3.1\",\"vectorString\":\"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H\",\"baseScore\":7.5,\"baseSeverity\":\"HIGH\",\"attackVector\":\"NETWORK\",\"attackComplexity\":\"LOW\",\"privilegesRequired\":\"NONE\",\"userInteraction\":\"NONE\",\"scope\":\"UNCHANGED\",\"confidentialityImpact\":\"NONE\",\"integrityImpact\":\"NONE\",\"availabilityImpact\":\"HIGH\"},\"exploitabilityScore\":3.9,\"impactScore\":3.6}],\"ssvcV203\":[{\"source\":\"134c704f-9b21-4f2e-91b3-4a467353bcc0\",\"ssvcData\":{\"timestamp\":\"2026-06-23T16:06:30.546768Z\",\"id\":\"CVE-2026-54283\",\"options\":[{\"exploitation\":\"none\"},{\"automatable\":\"yes\"},{\"technicalImpact\":\"partial\"}],\"role\":\"CISA Coordinator\",\"version\":\"2.0.3\"}}]},\"weaknesses\":[{\"source\":\"security-advisories@github.com\",\"type\":\"Secondary\",\"description\":[{\"lang\":\"en\",\"value\":\"CWE-770\"}]}],\"configurations\":[{\"nodes\":[{\"operator\":\"OR\",\"negate\":false,\"cpeMatch\":[{\"vulnerable\":true,\"criteria\":\"cpe:2.3:a:encode:starlette:*:*:*:*:*:python:*:*\",\"versionStartIncluding\":\"0.4.1\",\"versionEndExcluding\":\"1.3.1\",\"matchCriteriaId\":\"2FDB02B2-DCF6-4F2C-B06B-78C015D16494\"}]}]}],\"references\":[{\"url\":\"https://github.com/Kludex/starlette/security/advisories/GHSA-82w8-qh3p-5jfq\",\"source\":\"security-advisories@github.com\",\"tags\":[\"Mitigation\",\"Vendor Advisory\"]}]}}",
    "redhat_vex": {
      "aggregate_severity": "Important",
      "current_release_date": "2026-07-23T22:23:16+00:00",
      "cve": "CVE-2026-54283",
      "id": "CVE-2026-54283",
      "initial_release_date": "2026-06-22T16:46:16.706000+00:00",
      "product_status:fixed": "12",
      "product_status:known_affected": "55",
      "product_status:known_not_affected": "211",
      "source": "Red Hat CSAF VEX",
      "status": "final",
      "title": "starlette: Starlette: request.form() limits silently ignored for application/x-www-form-urlencoded enable DoS",
      "url": "https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-54283.json",
      "version": "3"
    },
    "suse_vex": {
      "aggregate_severity": "important",
      "current_release_date": "2026-07-15T05:03:21Z",
      "cve": "CVE-2026-54283",
      "id": "CVE-2026-54283",
      "initial_release_date": "2026-06-19T01:49:50Z",
      "product_status:known_affected": "5",
      "product_status:recommended": "3",
      "source": "SUSE CSAF VEX",
      "status": "interim",
      "title": "SUSE CVE CVE-2026-54283",
      "url": "https://ftp.suse.com/pub/projects/security/csaf-vex/cve-2026-54283.json",
      "version": "6"
    },
    "vulnrichment": {
      "containers": "{\"cna\": {\"title\": \"Starlette: request.form() limits silently ignored for application/x-www-form-urlencoded enable DoS\", \"problemTypes\": [{\"descriptions\": [{\"cweId\": \"CWE-770\", \"lang\": \"en\", \"description\": \"CWE-770: Allocation of Resources Without Limits or Throttling\", \"type\": \"CWE\"}]}], \"metrics\": [{\"cvssV3_1\": {\"attackComplexity\": \"LOW\", \"attackVector\": \"NETWORK\", \"availabilityImpact\": \"HIGH\", \"baseScore\": 7.5, \"baseSeverity\": \"HIGH\", \"confidentialityImpact\": \"NONE\", \"integrityImpact\": \"NONE\", \"privilegesRequired\": \"NONE\", \"scope\": \"UNCHANGED\", \"userInteraction\": \"NONE\", \"vectorString\": \"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H\", \"version\": \"3.1\"}}], \"references\": [{\"name\": \"https://github.com/Kludex/starlette/security/advisories/GHSA-82w8-qh3p-5jfq\", \"tags\": [\"x_refsource_CONFIRM\"], \"url\": \"https://github.com/Kludex/starlette/security/advisories/GHSA-82w8-qh3p-5jfq\"}], \"affected\": [{\"vendor\": \"Kludex\", \"product\": \"starlette\", \"versions\": [{\"version\": \"\u003e= 0.4.1, \u003c 1.3.1\", \"status\": \"affected\"}]}], \"providerMetadata\": {\"orgId\": \"a0819718-46f1-4df5-94e2-005712e83aaa\", \"shortName\": \"GitHub_M\", \"dateUpdated\": \"2026-06-22T16:46:16.706Z\"}, \"descriptions\": [{\"lang\": \"en\", \"value\": \"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.\"}], \"source\": {\"advisory\": \"GHSA-82w8-qh3p-5jfq\", \"discovery\": \"UNKNOWN\"}}, \"adp\": [{\"title\": \"CISA ADP Vulnrichment\", \"metrics\": [{\"other\": {\"type\": \"ssvc\", \"content\": {\"id\": \"CVE-2026-54283\", \"role\": \"CISA Coordinator\", \"options\": [{\"Exploitation\": \"none\"}, {\"Automatable\": \"yes\"}, {\"Technical Impact\": \"partial\"}], \"version\": \"2.0.3\", \"timestamp\": \"2026-06-23T16:06:30.546768Z\"}}}], \"providerMetadata\": {\"orgId\": \"134c704f-9b21-4f2e-91b3-4a467353bcc0\", \"shortName\": \"CISA-ADP\", \"dateUpdated\": \"2026-06-23T16:06:34.955Z\"}}]}",
      "cveMetadata": "{\"cveId\": \"CVE-2026-54283\", \"assignerOrgId\": \"a0819718-46f1-4df5-94e2-005712e83aaa\", \"state\": \"PUBLISHED\", \"assignerShortName\": \"GitHub_M\", \"dateReserved\": \"2026-06-12T17:46:37.292Z\", \"datePublished\": \"2026-06-22T16:46:16.706Z\", \"dateUpdated\": \"2026-06-23T16:10:51.227Z\"}",
      "dataType": "CVE_RECORD",
      "dataVersion": "5.2"
    }
  }
}



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.


Detection rules are retrieved from Rulezet.