{"id":"CVE-2026-11771","state":"PUBLISHED","title":"OpenVPN version 2.1.0 through 2.6.20 and 2.7_alpha1 through 2.7.4 allows attackers via an off-by-one buffer write in the NTLM proxy authentication to potentially cause a crash via ","description":"OpenVPN version 2.1.0 through 2.6.20 and 2.7_alpha1 through 2.7.4 allows attackers via an off-by-one buffer write in the NTLM proxy authentication to potentially cause a crash via a crafted NTLM response from a malicious proxy server","publishedAt":"2026-07-30T16:36:41.087Z","updatedAt":"2026-07-30T18:04:42.335Z","severity":{"score":7,"label":"High","version":"4.0","vector":"CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:P/VC:N/VI:N/VA:H/SC:N/SI:N/SA:H","source":"OpenVPN"},"assigner":"OpenVPN","products":["OpenVPN OpenVPN"],"affected":[{"vendor":"OpenVPN","product":"OpenVPN","defaultStatus":"unaffected","versions":[{"version":"2.1.0","status":"affected","lessThanOrEqual":"2.6.20","versionType":"semver"},{"version":"2.7_alpha1","status":"affected","lessThanOrEqual":"2.7.4","versionType":"semver"}]}],"references":["https://community.openvpn.net/Security%20Announcements/CVE-2026-11771","https://community.openvpn.net/ReleaseHistory#openvpn-275-released-1-july-2026","https://community.openvpn.net/ReleaseHistory#openvpn-2621-released-1-july-2026"],"weaknesses":["CWE-193","CWE-121","CWE-787"],"ingestedAt":"2026-10-29T20:10:52.580Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/11xxx/CVE-2026-11771.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-11771","state":"PUBLISHED","datePublished":"2026-07-30T16:36:41.087Z","dateUpdated":"2026-07-30T18:04:42.335Z","assignerShortName":"OpenVPN","assignerOrgId":"36a55730-e66d-4d39-8ca6-3c3b3017965e","dateReserved":"2026-06-09T11:44:10.570Z"},"containers":{"cna":{"descriptions":[{"lang":"en","value":"OpenVPN version 2.1.0 through 2.6.20 and 2.7_alpha1 through 2.7.4 allows attackers via an off-by-one buffer write in the NTLM proxy authentication to potentially cause a crash via a crafted NTLM response from a malicious proxy server"}],"affected":[{"vendor":"OpenVPN","product":"OpenVPN","defaultStatus":"unaffected","versions":[{"version":"2.1.0","status":"affected","lessThanOrEqual":"2.6.20","versionType":"semver"},{"version":"2.7_alpha1","status":"affected","lessThanOrEqual":"2.7.4","versionType":"semver"}]}],"references":[{"url":"https://community.openvpn.net/Security%20Announcements/CVE-2026-11771","tags":["vendor-advisory"]},{"url":"https://community.openvpn.net/ReleaseHistory#openvpn-275-released-1-july-2026","tags":["release-notes"]},{"url":"https://community.openvpn.net/ReleaseHistory#openvpn-2621-released-1-july-2026","tags":["release-notes"]}],"metrics":[{"format":"CVSS","scenarios":[{"lang":"en","value":"GENERAL"}],"cvssV4_0":{"attackVector":"NETWORK","attackComplexity":"HIGH","attackRequirements":"PRESENT","privilegesRequired":"NONE","userInteraction":"PASSIVE","vulnConfidentialityImpact":"NONE","subConfidentialityImpact":"NONE","vulnIntegrityImpact":"NONE","subIntegrityImpact":"NONE","vulnAvailabilityImpact":"HIGH","subAvailabilityImpact":"HIGH","exploitMaturity":"NOT_DEFINED","Safety":"NOT_DEFINED","Automatable":"NOT_DEFINED","Recovery":"NOT_DEFINED","valueDensity":"NOT_DEFINED","vulnerabilityResponseEffort":"NOT_DEFINED","providerUrgency":"NOT_DEFINED","version":"4.0","baseSeverity":"HIGH","baseScore":7,"vectorString":"CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:P/VC:N/VI:N/VA:H/SC:N/SI:N/SA:H"}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-193","lang":"en","description":"CWE-193 Off-by-one error","type":"CWE"}]},{"descriptions":[{"cweId":"CWE-121","lang":"en","description":"CWE-121 Stack-based buffer overflow","type":"CWE"}]},{"descriptions":[{"cweId":"CWE-787","lang":"en","description":"CWE-787 Out-of-bounds write","type":"CWE"}]}],"providerMetadata":{"shortName":"OpenVPN","orgId":"36a55730-e66d-4d39-8ca6-3c3b3017965e","dateUpdated":"2026-07-30T16:36:41.087Z"},"x_generator":{"engine":"cvelib 1.8.0"}},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-07-30T18:04:28.530958Z","id":"CVE-2026-11771","options":[{"Exploitation":"none"},{"Automatable":"no"},{"Technical Impact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-07-30T18:04:42.335Z"}}]}}}