High 7.7Published Oct 7, 2026

CVE-2026-83540wolfSSHd on Windows race condition leading to logon token reused across connections

Updated under an hour ago (2026-10-19 06:20 UTC)

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It affects wolfSSL wolfSSH and 1 other product. Add what you run to find out whether that includes you.

EPSS puts the chance of exploitation in the next 30 days at 0.36%, higher than 29% of scored CVEs.

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Every CVE for wolfSSL wolfSSH

Exploited in the last 30 days

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.

CVSS: 7.7 HIGH (v4.0, CNA)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
Weakness (CWE): CWE-287, CWE-613
Known exploited: Not in CISA's KEV catalog
EPSS (exploitation in the next 30 days): 0.36% (percentile 29)
Assigned by: wolfSSL
NVD analysis: Analyzed
Record last updated: Oct 7, 2026
First seen by InfoSec Signals: Oct 9, 2026

Affected products

Affected products

wolfSSL wolfSSH wolfssl:wolfssh (from the name)	from 1.4.15 through 1.5.0; fixed at 1.6.0	CNA record
wolfssh wolfssh wolfssh:wolfssh	from 1.4.15 before 1.6.0	NVD

References

https://github.com/wolfSSL/wolfsshproduct
https://github.com/wolfSSL/wolfssh/commit/b6bd975ccfac6aadf29b98e35e09114bef3840a9patch
https://github.com/wolfSSL/wolfssh/commit/9777bc5ce810d6c418a1473e9e8c40cdb0026e5apatch
https://www.wolfssl.com/docs/security-vulnerabilities/vendor-advisory

The CVE record on cve.org NVD's entry

The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.