SvelteKit has a memory amplification DoS in Remote Functions binary form deserializer

{
  "id": "36f7755e88d3a36daefa6574d18f1c62e53638480e9a7d8999c75fa5cd150709",
  "url": "https://osv.dev/vulnerability/CVE-2026-22803",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "SvelteKit has a memory amplification DoS in Remote Functions binary form deserializer",
    "summary": "SvelteKit is a framework for rapidly developing robust, performant web applications using Svelte. From 2.49.0 to 2.49.4, the experimental form remote function uses a binary data format containing a representation of submitted form data. A specially-crafted payload can cause the server to allocate a large amount of memory, causing DoS via memory exhaustion. This vulnerability is fixed in 2.49.5.",
    "evidence": "osv:CVE-2026-22803",
    "products": [],
    "severity": "high",
    "structured": {
      "id": "CVE-2026-22803",
      "aliases": [
        "CVE-2026-22803",
        "GHSA-j2f3-wq62-6q46"
      ],
      "metrics": [
        {
          "type": "CVSS_V4",
          "score": "CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://github.com/sveltejs/kit",
              "type": "GIT",
              "events": [
                {
                  "introduced": "ab3784911accefd8d3bc292a80d8e3b825528fd3"
                },
                {
                  "fixed": "80ffb53382e397a8fc83e6b63d2675eeabb427bd"
                },
                {
                  "fixed": "8ed8155215b9a74012fecffb942ad9a793b274e5"
                }
              ],
              "database_specific": {
                "extracted_events": [
                  {
                    "cpe": "cpe:2.3:a:svelte:kit:*:*:*:*:*:node.js:*:*",
                    "range": [
                      {
                        "introduced": "2.49.0"
                      },
                      {
                        "fixed": "2.49.5"
                      }
                    ],
                    "source": "CPE_RANGE"
                  },
                  {
                    "range": [
                      {
                        "fixed": "8ed8155215b9a74012fecffb942ad9a793b274e5"
                      }
                    ],
                    "source": "REFERENCES_COMMIT"
                  }
                ]
              }
            }
          ],
          "versions": [
            "@sveltejs/adapter-node@5.5.0",
            "@sveltejs/kit@2.49.4",
            "@sveltejs/kit@2.49.3",
            "@sveltejs/adapter-vercel@6.3.0",
            "@sveltejs/kit@2.49.2",
            "@sveltejs/kit@2.49.1",
            "@sveltejs/package@2.5.7",
            "@sveltejs/enhanced-img@0.9.2",
            "@sveltejs/adapter-vercel@6.2.0",
            "@sveltejs/enhanced-img@0.9.1",
            "@sveltejs/kit@2.49.0"
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-22803.json"
          }
        }
      ],
      "modified": "2026-10-28T02:30:38.038846986Z",
      "provider": "osv",
      "references": [
        "https://github.com/sveltejs/kit/releases/tag/@sveltejs%2Fadapter-node@5.5.1",
        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/22xxx/CVE-2026-22803.json",
        "https://github.com/sveltejs/kit/security/advisories/GHSA-j2f3-wq62-6q46",
        "https://nvd.nist.gov/vuln/detail/CVE-2026-22803",
        "https://github.com/sveltejs/kit/commit/8ed8155215b9a74012fecffb942ad9a793b274e5"
      ],
      "provider_metadata": {
        "cwe_ids": [
          "CWE-789"
        ],
        "cna_assigner": "GitHub_M",
        "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/22xxx/CVE-2026-22803.json"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2026-22803",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 505098,
  "published_at": "2026-01-15T18:37:57.831+00:00"
}