{"id":"CVE-2026-83540","aliases":["ALPINE-CVE-2026-83540","EUVD-2026-94163","GHSA-36jf-xmwg-5wp8"],"status":"published","title":"wolfSSHd on Windows race condition leading to logon token reused across connections","description":"When password or public key authentication is used with the Windows port of wolfSSHd, the Windows logon token acquired for one authenticated connection is not released before a token is acquired for a subsequent connection, resulting in user login poisoning between connections. A less privileged user with a valid account on the server can exploit this to force a login as a more privileged user. The vulnerability was introduced with the initial Windows port of wolfSSHd in wolfSSH version 1.4.15 and affects all versions through 1.5.0. Non-Windows builds of wolfSSHd are not affected.","severity":{"version":"4.0","score":7.7,"vector":"CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N","level":"high","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-10","score":0.00552,"percentile":0.46478,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":true},"cwes":["CWE-287","CWE-613"],"published":"2026-10-07T02:40:35Z","modified":"2026-11-03T06:32:57Z","fixes":[{"ecosystem":"Alpine:v3.24","package":"wolfssh","fixed_in":["1.6.0-r0"],"sources":["osv"]}],"affected":[{"source":"osv","ecosystem":"Alpine:v3.24","package":"wolfssh","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"1.4.15"},{"fixed":"1.6.0-r0"}]}]}],"products":[{"vendor":"wolfssh","product":"wolfssh"},{"vendor":"wolfssl","product":"wolfssh"}],"references":[{"url":"https://github.com/wolfSSL/wolfssh","tags":["product","Product","package"]},{"url":"https://github.com/wolfSSL/wolfssh/commit/b6bd975ccfac6aadf29b98e35e09114bef3840a9","tags":["patch","Patch","fix"]},{"url":"https://github.com/wolfSSL/wolfssh/commit/9777bc5ce810d6c418a1473e9e8c40cdb0026e5a","tags":["patch","Patch","fix"]},{"url":"https://www.wolfssl.com/docs/security-vulnerabilities/","tags":["vendor-advisory","Vendor Advisory","advisory"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-83540","tags":["advisory"]},{"url":"https://www.wolfssl.com/docs/security-vulnerabilities"},{"url":"https://github.com/advisories/GHSA-36jf-xmwg-5wp8"},{"url":"https://security.alpinelinux.org/vuln/CVE-2026-83540","tags":["advisory"]},{"url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/83xxx/CVE-2026-83540.json","tags":["advisory"]}],"sources":{"cve":[{"id":"CVE-2026-83540","title":"wolfSSHd on Windows race condition leading to logon token reused across connections","description":"When password or public key authentication is used with the Windows port of wolfSSHd, the Windows logon token acquired for one authenticated connection is not released before a token is acquired for a subsequent connection, resulting in user login poisoning between connections. A less privileged user with a valid account on the server can exploit this to force a login as a more privileged user. The vulnerability was introduced with the initial Windows port of wolfSSHd in wolfSSH version 1.4.15 and affects all versions through 1.5.0. Non-Windows builds of wolfSSHd are not affected.","status":"published","published":"2026-10-07T02:40:35.137Z","modified":"2026-10-07T11:29:08.132Z","cvss":[{"version":"4.0","score":7.7,"vector":"CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N","level":"high","assessor":"cna"}],"cwes":["CWE-287","CWE-613"],"updated_at":"2026-11-02T13:44:51.734189Z"}],"euvd":[{"id":"EUVD-2026-94163","description":"When password or public key authentication is used with the Windows port of wolfSSHd, the Windows logon token acquired for one authenticated connection is not released before a token is acquired for a subsequent connection, resulting in user login poisoning between connections. A less privileged user with a valid account on the server can exploit this to force a login as a more privileged user. The vulnerability was introduced with the initial Windows port of wolfSSHd in wolfSSH version 1.4.15 and affects all versions through 1.5.0. Non-Windows builds of wolfSSHd are not affected.","status":"published","published":"2026-10-07T02:40:35Z","modified":"2026-10-07T11:29:08Z","cvss":[{"version":"4.0","score":7.7,"vector":"CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N","level":"high"}],"updated_at":"2026-11-02T17:27:35.509652Z"}],"ghsa":[{"id":"GHSA-36jf-xmwg-5wp8","title":"When password or public key authentication is used with the Windows port of wolfSSHd, the Windows...","description":"When password or public key authentication is used with the Windows port of wolfSSHd, the Windows logon token acquired for one authenticated connection is not released before a token is acquired for a subsequent connection, resulting in user login poisoning between connections. A less privileged user with a valid account on the server can exploit this to force a login as a more privileged user. The vulnerability was introduced with the initial Windows port of wolfSSHd in wolfSSH version 1.4.15 and affects all versions through 1.5.0. Non-Windows builds of wolfSSHd are not affected.","status":"published","published":"2026-10-07T03:30:23Z","modified":"2026-10-13T18:31:30Z","cvss":[{"version":"4.0","score":7.7,"vector":"CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:H/VI:H/VA:H/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","level":"high"},{"version":"3.1","score":8.8,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","level":"high"}],"cwes":["CWE-287"],"updated_at":"2026-11-02T15:13:12.080152Z"}],"nvd":[{"id":"CVE-2026-83540","description":"When password or public key authentication is used with the Windows port of wolfSSHd, the Windows logon token acquired for one authenticated connection is not released before a token is acquired for a subsequent connection, resulting in user login poisoning between connections. A less privileged user with a valid account on the server can exploit this to force a login as a more privileged user. The vulnerability was introduced with the initial Windows port of wolfSSHd in wolfSSH version 1.4.15 and affects all versions through 1.5.0. Non-Windows builds of wolfSSHd are not affected.","status":"published","published":"2026-10-07T03:16:59.73Z","modified":"2026-10-13T17:33:17.707Z","cvss":[{"version":"4.0","score":7.7,"vector":"CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:H/VI:H/VA:H/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","level":"high","assessor":"secondary"},{"version":"3.1","score":8.8,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","level":"high","assessor":"primary"}],"cwes":["CWE-287","CWE-613"],"updated_at":"2026-11-02T14:12:54.809359Z"}],"osv":[{"id":"ALPINE-CVE-2026-83540","description":"When password or public key authentication is used with the Windows port of wolfSSHd, the Windows logon token acquired for one authenticated connection is not released before a token is acquired for a subsequent connection, resulting in user login poisoning between connections. A less privileged user with a valid account on the server can exploit this to force a login as a more privileged user. The vulnerability was introduced with the initial Windows port of wolfSSHd in wolfSSH version 1.4.15 and affects all versions through 1.5.0. Non-Windows builds of wolfSSHd are not affected.","status":"published","published":"2026-10-07T03:16:59.73Z","modified":"2026-11-03T06:32:57.083393207Z","cvss":[{"version":"3.1","score":8.8,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","level":"high"}],"updated_at":"2026-11-03T07:16:26.770911Z"},{"id":"CVE-2026-83540","title":"wolfSSHd on Windows race condition leading to logon token reused across connections","description":"When password or public key authentication is used with the Windows port of wolfSSHd, the Windows logon token acquired for one authenticated connection is not released before a token is acquired for a subsequent connection, resulting in user login poisoning between connections. A less privileged user with a valid account on the server can exploit this to force a login as a more privileged user. The vulnerability was introduced with the initial Windows port of wolfSSHd in wolfSSH version 1.4.15 and affects all versions through 1.5.0. Non-Windows builds of wolfSSHd are not affected.","status":"published","published":"2026-10-07T02:40:35.137Z","modified":"2026-10-28T11:18:44.951911254Z","cvss":[{"version":"4.0","score":7.7,"vector":"CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N","level":"high"}],"cwes":["CWE-287","CWE-613"],"updated_at":"2026-11-02T15:45:18.482949Z"}]}}