CVE-2026-83540 (GCVE-0-2026-83540)
Vulnerability from cvelistv5
Published
2026-10-07 02:40
Modified
2026-10-07 11:29
Severity ?
VLAI Severity ?
EPSS score ?
Summary
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.
References
| URL | Tags | |
|---|---|---|
{
"containers": {
"adp": [
{
"metrics": [
{
"other": {
"content": {
"id": "CVE-2026-83540",
"options": [
{
"Exploitation": "none"
},
{
"Automatable": "no"
},
{
"Technical Impact": "total"
}
],
"role": "CISA Coordinator",
"timestamp": "2026-10-07T11:28:54.655733Z",
"version": "2.0.3"
},
"type": "ssvc"
}
}
],
"providerMetadata": {
"dateUpdated": "2026-10-07T11:29:08.132Z",
"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"shortName": "CISA-ADP"
},
"title": "CISA ADP Vulnrichment"
}
],
"cna": {
"affected": [
{
"collectionURL": "https://github.com/wolfSSL/wolfssh",
"defaultStatus": "unaffected",
"modules": [
"wolfSSHd"
],
"platforms": [
"Windows"
],
"product": "wolfSSH",
"programFiles": [
"apps/wolfsshd/auth.c"
],
"programRoutines": [
{
"name": "SetupUserTokenWin"
},
{
"name": "CheckPasswordWIN"
}
],
"repo": "https://github.com/wolfSSL/wolfssh",
"vendor": "wolfSSL",
"versions": [
{
"changes": [
{
"at": "1.6.0",
"status": "unaffected"
}
],
"lessThanOrEqual": "1.5.0",
"status": "affected",
"version": "1.4.15",
"versionType": "semver"
}
]
}
],
"configurations": [
{
"lang": "en",
"supportingMedia": [
{
"base64": false,
"type": "text/html",
"value": "\u003cp\u003ewolfSSHd built for and running on Windows with password or public key authentication enabled.\u003c/p\u003e"
}
],
"value": "wolfSSHd built for and running on Windows with password or public key authentication enabled."
}
],
"credits": [
{
"lang": "en",
"type": "finder",
"value": "Found by internal wolfSSL testing"
}
],
"descriptions": [
{
"lang": "en",
"supportingMedia": [
{
"base64": false,
"type": "text/html",
"value": "\u003cp\u003eWhen 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.\u003c/p\u003e"
}
],
"value": "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."
}
],
"impacts": [
{
"capecId": "CAPEC-233",
"descriptions": [
{
"lang": "en",
"value": "CAPEC-233 Privilege Escalation"
}
]
}
],
"metrics": [
{
"cvssV4_0": {
"Automatable": "NOT_DEFINED",
"Recovery": "NOT_DEFINED",
"Safety": "NOT_DEFINED",
"attackComplexity": "LOW",
"attackRequirements": "PRESENT",
"attackVector": "NETWORK",
"baseScore": 7.7,
"baseSeverity": "HIGH",
"exploitMaturity": "NOT_DEFINED",
"privilegesRequired": "LOW",
"providerUrgency": "NOT_DEFINED",
"subAvailabilityImpact": "NONE",
"subConfidentialityImpact": "NONE",
"subIntegrityImpact": "NONE",
"userInteraction": "NONE",
"valueDensity": "NOT_DEFINED",
"vectorString": "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",
"version": "4.0",
"vulnAvailabilityImpact": "HIGH",
"vulnConfidentialityImpact": "HIGH",
"vulnIntegrityImpact": "HIGH",
"vulnerabilityResponseEffort": "NOT_DEFINED"
},
"format": "CVSS",
"scenarios": [
{
"lang": "en",
"value": "GENERAL"
}
]
}
],
"problemTypes": [
{
"descriptions": [
{
"cweId": "CWE-287",
"description": "CWE-287 Improper Authentication",
"lang": "en",
"type": "CWE"
},
{
"cweId": "CWE-613",
"description": "CWE-613 Insufficient Session Expiration",
"lang": "en",
"type": "CWE"
}
]
}
],
"providerMetadata": {
"dateUpdated": "2026-10-07T02:40:35.137Z",
"orgId": "50d2cd11-d01a-48ed-9441-5bfce9d63b27",
"shortName": "wolfSSL"
},
"references": [
{
"name": "wolfSSH source repository",
"tags": [
"product"
],
"url": "https://github.com/wolfSSL/wolfssh"
},
{
"name": "Fix: give each Windows wolfSSHd connection its own authentication context",
"tags": [
"patch"
],
"url": "https://github.com/wolfSSL/wolfssh/commit/b6bd975ccfac6aadf29b98e35e09114bef3840a9"
},
{
"name": "Fix: add Windows sanity close of token before acquiring a new one",
"tags": [
"patch"
],
"url": "https://github.com/wolfSSL/wolfssh/commit/9777bc5ce810d6c418a1473e9e8c40cdb0026e5a"
},
{
"name": "wolfSSL security vulnerabilities page",
"tags": [
"vendor-advisory"
],
"url": "https://www.wolfssl.com/docs/security-vulnerabilities/"
}
],
"source": {
"discovery": "UNKNOWN"
},
"title": "wolfSSHd on Windows race condition leading to logon token reused across connections",
"workarounds": [
{
"lang": "en",
"supportingMedia": [
{
"base64": false,
"type": "text/html",
"value": "\u003cp\u003eRestrict 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.\u003c/p\u003e"
}
],
"value": "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."
}
],
"x_generator": {
"engine": "Vulnogram 0.2.0"
}
}
},
"cveMetadata": {
"assignerOrgId": "50d2cd11-d01a-48ed-9441-5bfce9d63b27",
"assignerShortName": "wolfSSL",
"cveId": "CVE-2026-83540",
"datePublished": "2026-10-07T02:40:35.137Z",
"dateReserved": "2026-08-31T17:29:54.256Z",
"dateUpdated": "2026-10-07T11:29:08.132Z",
"state": "PUBLISHED"
},
"dataType": "CVE_RECORD",
"dataVersion": "5.2",
"vulnerability-lookup:meta": {
"vulnrichment": {
"containers": "{\"adp\": [{\"title\": \"CISA ADP Vulnrichment\", \"metrics\": [{\"other\": {\"type\": \"ssvc\", \"content\": {\"id\": \"CVE-2026-83540\", \"role\": \"CISA Coordinator\", \"options\": [{\"Exploitation\": \"none\"}, {\"Automatable\": \"no\"}, {\"Technical Impact\": \"total\"}], \"version\": \"2.0.3\", \"timestamp\": \"2026-10-07T11:28:54.655733Z\"}}}], \"providerMetadata\": {\"orgId\": \"134c704f-9b21-4f2e-91b3-4a467353bcc0\", \"shortName\": \"CISA-ADP\", \"dateUpdated\": \"2026-10-07T11:29:02.152Z\"}}], \"cna\": {\"title\": \"wolfSSHd on Windows race condition leading to logon token reused across connections\", \"source\": {\"discovery\": \"UNKNOWN\"}, \"credits\": [{\"lang\": \"en\", \"type\": \"finder\", \"value\": \"Found by internal wolfSSL testing\"}], \"impacts\": [{\"capecId\": \"CAPEC-233\", \"descriptions\": [{\"lang\": \"en\", \"value\": \"CAPEC-233 Privilege Escalation\"}]}], \"metrics\": [{\"format\": \"CVSS\", \"cvssV4_0\": {\"Safety\": \"NOT_DEFINED\", \"version\": \"4.0\", \"Recovery\": \"NOT_DEFINED\", \"baseScore\": 7.7, \"Automatable\": \"NOT_DEFINED\", \"attackVector\": \"NETWORK\", \"baseSeverity\": \"HIGH\", \"valueDensity\": \"NOT_DEFINED\", \"vectorString\": \"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\", \"exploitMaturity\": \"NOT_DEFINED\", \"providerUrgency\": \"NOT_DEFINED\", \"userInteraction\": \"NONE\", \"attackComplexity\": \"LOW\", \"attackRequirements\": \"PRESENT\", \"privilegesRequired\": \"LOW\", \"subIntegrityImpact\": \"NONE\", \"vulnIntegrityImpact\": \"HIGH\", \"subAvailabilityImpact\": \"NONE\", \"vulnAvailabilityImpact\": \"HIGH\", \"subConfidentialityImpact\": \"NONE\", \"vulnConfidentialityImpact\": \"HIGH\", \"vulnerabilityResponseEffort\": \"NOT_DEFINED\"}, \"scenarios\": [{\"lang\": \"en\", \"value\": \"GENERAL\"}]}], \"affected\": [{\"repo\": \"https://github.com/wolfSSL/wolfssh\", \"vendor\": \"wolfSSL\", \"modules\": [\"wolfSSHd\"], \"product\": \"wolfSSH\", \"versions\": [{\"status\": \"affected\", \"changes\": [{\"at\": \"1.6.0\", \"status\": \"unaffected\"}], \"version\": \"1.4.15\", \"versionType\": \"semver\", \"lessThanOrEqual\": \"1.5.0\"}], \"platforms\": [\"Windows\"], \"programFiles\": [\"apps/wolfsshd/auth.c\"], \"collectionURL\": \"https://github.com/wolfSSL/wolfssh\", \"defaultStatus\": \"unaffected\", \"programRoutines\": [{\"name\": \"SetupUserTokenWin\"}, {\"name\": \"CheckPasswordWIN\"}]}], \"references\": [{\"url\": \"https://github.com/wolfSSL/wolfssh\", \"name\": \"wolfSSH source repository\", \"tags\": [\"product\"]}, {\"url\": \"https://github.com/wolfSSL/wolfssh/commit/b6bd975ccfac6aadf29b98e35e09114bef3840a9\", \"name\": \"Fix: give each Windows wolfSSHd connection its own authentication context\", \"tags\": [\"patch\"]}, {\"url\": \"https://github.com/wolfSSL/wolfssh/commit/9777bc5ce810d6c418a1473e9e8c40cdb0026e5a\", \"name\": \"Fix: add Windows sanity close of token before acquiring a new one\", \"tags\": [\"patch\"]}, {\"url\": \"https://www.wolfssl.com/docs/security-vulnerabilities/\", \"name\": \"wolfSSL security vulnerabilities page\", \"tags\": [\"vendor-advisory\"]}], \"workarounds\": [{\"lang\": \"en\", \"value\": \"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.\", \"supportingMedia\": [{\"type\": \"text/html\", \"value\": \"\u003cp\u003eRestrict 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.\u003c/p\u003e\", \"base64\": false}]}], \"x_generator\": {\"engine\": \"Vulnogram 0.2.0\"}, \"descriptions\": [{\"lang\": \"en\", \"value\": \"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.\", \"supportingMedia\": [{\"type\": \"text/html\", \"value\": \"\u003cp\u003eWhen 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.\u003c/p\u003e\", \"base64\": false}]}], \"problemTypes\": [{\"descriptions\": [{\"lang\": \"en\", \"type\": \"CWE\", \"cweId\": \"CWE-287\", \"description\": \"CWE-287 Improper Authentication\"}, {\"lang\": \"en\", \"type\": \"CWE\", \"cweId\": \"CWE-613\", \"description\": \"CWE-613 Insufficient Session Expiration\"}]}], \"configurations\": [{\"lang\": \"en\", \"value\": \"wolfSSHd built for and running on Windows with password or public key authentication enabled.\", \"supportingMedia\": [{\"type\": \"text/html\", \"value\": \"\u003cp\u003ewolfSSHd built for and running on Windows with password or public key authentication enabled.\u003c/p\u003e\", \"base64\": false}]}], \"providerMetadata\": {\"orgId\": \"50d2cd11-d01a-48ed-9441-5bfce9d63b27\", \"shortName\": \"wolfSSL\", \"dateUpdated\": \"2026-10-07T02:40:35.137Z\"}}}",
"cveMetadata": "{\"cveId\": \"CVE-2026-83540\", \"state\": \"PUBLISHED\", \"dateUpdated\": \"2026-10-07T11:29:08.132Z\", \"dateReserved\": \"2026-08-31T17:29:54.256Z\", \"assignerOrgId\": \"50d2cd11-d01a-48ed-9441-5bfce9d63b27\", \"datePublished\": \"2026-10-07T02:40:35.137Z\", \"assignerShortName\": \"wolfSSL\"}",
"dataType": "CVE_RECORD",
"dataVersion": "5.2"
}
}
}
Loading…
Loading…
Sightings
| Author | Source | Type | Date |
|---|
Nomenclature
- Seen: The vulnerability was mentioned, discussed, or seen somewhere by the user.
- Confirmed: The vulnerability is confirmed from an analyst perspective.
- Published Proof of Concept: A public proof of concept is available for this vulnerability.
- Exploited: This vulnerability was exploited and seen by the user reporting the sighting.
- Patched: This vulnerability was successfully patched by the user reporting the sighting.
- Not exploited: This vulnerability was not exploited or seen by the user reporting the sighting.
- Not confirmed: The user expresses doubt about the veracity of the vulnerability.
- Not patched: This vulnerability was not successfully patched by the user reporting the sighting.
Loading…
Loading…