CVE-2026-83540

wolfSSHd on Windows race condition leading to logon token reused across connections

Published Oct 7, 2026 CVSS 4.0 · 7.7 High EPSS < 1% KEV · Not listed
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.

Remediation

Vendor Workaround

Restrict which accounts may connect to the affected wolfSSHd instance on Windows hosts until the server is upgraded. Disabling public key authentication alone does not help, because password authentication is affected as well.

Tracking

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Advisories

No advisories available
History
Type Values Removed Values Added
First Time appeared Wolfssh
Wolfssh wolfssh
CPEs cpe:2.3:a:wolfssh:wolfssh:*:*:*:*:*:*:*:*
Vendors & Products Wolfssh
Wolfssh wolfssh
Metrics cvssV3_1

{'score': 8.8, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H'}

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'total'}, 'version': '2.0.3'}

Type Values Removed Values Added
First Time appeared Wolfssl
Wolfssl wolfssh
Vendors & Products Wolfssl
Wolfssl wolfssh
Type Values Removed Values Added
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.
Title wolfSSHd on Windows race condition leading to logon token reused across connections
Weaknesses CWE-287
CWE-613
References
Metrics cvssV4_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'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
wolfSSL
Published
Updated
Oct 7, 2026, 11:29 AM
Reserved
Aug 31, 2026, 5:29 PM
Status
Analyzed
Published
Oct 7, 2026, 3:16 AM
Modified
Oct 13, 2026, 5:33 PM