{"id":"CVE-2019-1338","aliases":["EUVD-2019-9896","GHSA-qm7q-vxj7-9xg3"],"status":"published","title":"A security feature bypass vulnerability exists in Microsoft Windows when a man-in-the-middle...","description":"A security feature bypass vulnerability exists in Microsoft Windows when a man-in-the-middle attacker is able to successfully bypass the NTLMv2 protection if a client is also sending LMv2 responses, aka 'Windows NTLM Security Feature Bypass Vulnerability'.","severity":{"version":"3.1","score":5.9,"vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:N","level":"medium","assessor":"primary","from":"nvd"},"epss":{"day":"2026-11-08","score":0.03555,"percentile":0.894,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":false},"cwes":["CWE-326"],"published":"2019-10-10T13:28:41Z","modified":"2026-06-17T02:28:24Z","products":[{"vendor":"microsoft","product":"windows"},{"vendor":"microsoft","product":"windows server"},{"vendor":"microsoft","product":"windows_7"},{"vendor":"microsoft","product":"windows_server_2008"}],"references":[{"url":"https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2019-1338","tags":["x_refsource_MISC","x_transferred","Patch","Vendor Advisory"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2019-1338"},{"url":"https://github.com/advisories/GHSA-qm7q-vxj7-9xg3"}],"sources":{"cve":[{"id":"CVE-2019-1338","description":"A security feature bypass vulnerability exists in Microsoft Windows when a man-in-the-middle attacker is able to successfully bypass the NTLMv2 protection if a client is also sending LMv2 responses, aka 'Windows NTLM Security Feature Bypass Vulnerability'.","status":"published","published":"2019-10-10T13:28:41Z","modified":"2024-08-04T18:13:30.487Z","updated_at":"2026-11-02T14:20:25.661187Z"}],"euvd":[{"id":"EUVD-2019-9896","description":"A security feature bypass vulnerability exists in Microsoft Windows when a man-in-the-middle attacker is able to successfully bypass the NTLMv2 protection if a client is also sending LMv2 responses, aka 'Windows NTLM Security Feature Bypass Vulnerability'.","status":"published","published":"2019-10-10T13:28:41Z","modified":"2024-08-04T18:13:30Z","updated_at":"2026-11-03T03:06:58.233851Z"}],"ghsa":[{"id":"GHSA-qm7q-vxj7-9xg3","title":"A security feature bypass vulnerability exists in Microsoft Windows when a man-in-the-middle...","description":"A security feature bypass vulnerability exists in Microsoft Windows when a man-in-the-middle attacker is able to successfully bypass the NTLMv2 protection if a client is also sending LMv2 responses, aka 'Windows NTLM Security Feature Bypass Vulnerability'.","status":"published","published":"2022-05-24T16:58:28Z","modified":"2023-01-28T05:07:20Z","cwes":["CWE-326"],"updated_at":"2026-11-02T14:44:31.117774Z"}],"nvd":[{"id":"CVE-2019-1338","description":"A security feature bypass vulnerability exists in Microsoft Windows when a man-in-the-middle attacker is able to successfully bypass the NTLMv2 protection if a client is also sending LMv2 responses, aka 'Windows NTLM Security Feature Bypass Vulnerability'.","status":"published","published":"2019-10-10T14:15:17.097Z","modified":"2026-06-17T02:28:24.68Z","cvss":[{"version":"3.1","score":5.9,"vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:N","level":"medium","assessor":"primary"},{"version":"2.0","score":4.3,"vector":"AV:N/AC:M/Au:N/C:N/I:P/A:N","level":"medium","assessor":"primary"}],"updated_at":"2026-11-02T14:05:31.019577Z"}]}}