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Vulnerabilities/CVE-2026-83540Public Intelligence Dossier
Source: wolfssh · Limited verification•Last verified: •Collection Running
CVE-2026-83540Unknown / EvaluatingHIGH (raw)CVSS 8.8CWE-287

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

Published: 07 Oct 2026•Last updated: 13 Oct 2026, 11:03 PM IST•Source identifier: facts@wolfssl.com
Dossier completeness: source-provided sections 2 / 3 · rule guidance available. Missing source facts count as incomplete.
Official source
CISA KEV catalog
Unknown
KEV status was not determined.
CVSS score
8.8HIGH (raw)
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Metric sourcenvd@nist.gov
EPSS probability
0.4%0.004
Percentile29th
Weakness type
CWE-287
CWE-613
Remediation
Patch status unknown
No fixed version or KB recorded

Why It Matters

Analysis dossier

Why It Matters

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.

SOC priority

High

Actively exploited

Unknown

Publicly disclosed

Unknown

Risk basis: Microsoft or Microsoft-managed product relevance; HIGH severity; No confirmed exploitation signal in current enrichment

Affected Products & Remediation

1 source-backed product
Affected products and versions (source)
  • wolfssh wolfssh · >= 1.4.15 < 1.6.0 · NVD CPE · Source
Recorded patch / KBNot provided by source

Vendor or catalog guidance (source)

Not provided by source

Known exploitation (source facts)

Only what a source states. Unknown means no source has said either way; it is not "not exploited".

CISA KEV
Unknown
Exploited (source statement)
Unknown
Publicly disclosed (source)
Unknown

Suggested hunting (rule-based inference)

SecOps Signal recommendation (rule-based inference). These steps are hunting hypotheses from the vulnerability class; they do not state or imply that exploitation occurred here or anywhere.

Matched authentication-weakness (CWE-287)

Exposure

  1. Identify affected authentication surfaces and compare versions with the advisory.Telemetry: Application inventory · A CWE match is not proof of local exposure. · Rule authentication-weakness

Exploitation evidence

  1. Review unexpected successful sign-ins and changes to privileged accounts on affected systems.Telemetry: SigninLogs · Access anomalies are relevant to authentication weaknesses. · Rule authentication-weakness

Response

  1. Verify the vendor fix and review privileged access after remediation.Telemetry: Identity audit logs · Post-change review checks the response. · Rule authentication-weakness

CISA KEV Record

CISA KEV status was not determined for this record.

Change History & Source Data

— No recorded material change

CNA / source
facts@wolfssl.com
Record status · verification
UPDATED · NVD API
CPE
cpe:2.3:a:wolfssh:wolfssh:*:*:*:*:*:*:*:*

Evidence & Provenance

3 public sources
github.comSource recordnvd.nist.govSource recordgithub.comSource record

Linked by the query's stored exact CVE association. Review required tables and validation status before use.

Detection Hunting Query
Target: DeviceTvmSoftwareVulnerabilities•Defender XDR
Detect endpoints exposed to CVE-2026-83540
Purpose: Exposure assessment (Category: Exposure Check)Why linked: Query metadata names CVE-2026-83540
DeviceTvmSoftwareVulnerabilities| where CveId == "CVE-2026-83540"| project DeviceId, DeviceName, OSPlatform, OSVersion, SoftwareVendor, SoftwareName, SoftwareVersion, CveId, VulnerabilitySeverityLevel, RecommendedSecurityUpdate, RecommendedSecurityUpdateId| sort by VulnerabilitySeverityLevel desc
Schema Checked · Not runtime validatedSource: SecOps Signal deterministic template · Limited verificationStatic screening: Passed structure and schema checks; tenant execution is not verified.
Open KQL Library

Correlated briefings

— No published briefing references this CVE

SecOps Signal surfaces public advisory facts only. A missing value means the source has not published it, not that your environment is unaffected. No tenant inventory is connected.