CVE-2026-81034
Netmaker disables certificate verification on the connection to the configured mail server. The sender in pro/email/smtp.go assigns a TLS configuration whose skip-verify field is set to true unconditionally, directly beneath a comment stating that the setting should be false in production. No configuration value governs it and no code path restores verification, so the client accepts any certificate the mail server presents, including one an interposing party supplies.
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Mail that Netmaker sends over that connection includes password-reset messages carrying single-use tokens and user invitations carrying enrolment links, so a party positioned on the path between the server and its mail relay can read those messages in transit and use a captured reset token before the intended recipient does. The setting is absent from the development branch but present in the latest release.
CVSS
- Versión: 4.0
- Vector: CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:L/VA:N/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
- Puntuación base: 8.3
Probabilidad de explotación (EPSS)
- Probabilidad de explotación en los próximos 30 días: 0.26%
- Percentil entre todas las CVEs puntuadas: 17
- Fecha de la puntuación: 6/10/2026
EPSS (Exploit Prediction Scoring System, de FIRST) estima la probabilidad de que una vulnerabilidad sea explotada en 30 días. Complementa a CVSS (impacto) y a CISA KEV (explotación confirmada).
🎯 Técnicas ATT&CK
Cómo se explota esta vulnerabilidad y qué consigue el atacante, en el lenguaje de MITRE ATT&CK.
- Explotación
T1557Adversary-in-the-Middlecredential access · collection85 % - Impacto principal
T1212Exploitation for Credential Accesscredential access90 % - Impacto secundario
T1021.006Windows Remote Managementlateral movement75 %
Vulnerabilidad de verificación TLS deshabilitada (CWE-295) permite MITM entre Netmaker y servidor SMTP (AV:N, red sin privilegios). El atacante captura tokens de reset y links de enrollment en mensajes de correo (T1212: credenciales/tokens), posibilitando acceso a cuentas (T1021.006: RDP/login remot
Inferido por nuestro agente de análisis a partir de la descripción oficial, el vector CVSS y la CWE, y comprobado por un supervisor. Puede contener errores.
🛡️ Mitigaciones ATT&CK que cubren estas técnicas
Tecnologías afectadas (1)
⚠ Inferidas por IA a partir de la descripción — NVD aún no ha analizado esta CVE; no son CPE verificados.
CWE
- CWE-295
Referencias
- https://github.com/gravitl/netmaker
- https://github.com/gravitl/netmaker/blob/v1.6.0/pro/email/smtp.go
- https://github.com/gravitl/netmaker/issues/4062
- https://www.vulncheck.com/advisories/netmaker-through-1.6.0-improper-certificate-validation-in-smtp-client
- https://github.com/gravitl/netmaker/issues/4062
JSON original (NVD)
Mostrar
{
"id": "CVE-2026-81034",
"cveTags": [],
"metrics": {
"ssvcV203": [
{
"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"ssvcData": {
"id": "CVE-2026-81034",
"role": "CISA Coordinator",
"options": [
{
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},
{
"automatable": "no"
},
{
"technicalImpact": "partial"
}
],
"version": "2.0.3",
"timestamp": "2026-08-26T18:30:06.108580Z"
}
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"cvssMetricV31": [
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"vectorString": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:L/A:N",
"integrityImpact": "LOW",
"userInteraction": "NONE",
"attackComplexity": "HIGH",
"availabilityImpact": "NONE",
"privilegesRequired": "NONE",
"confidentialityImpact": "HIGH"
},
"impactScore": 4.2,
"exploitabilityScore": 2.2
}
],
"cvssMetricV40": [
{
"type": "Secondary",
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"cvssData": {
"Safety": "NOT_DEFINED",
"version": "4.0",
"Recovery": "NOT_DEFINED",
"baseScore": 8.3,
"Automatable": "NOT_DEFINED",
"attackVector": "NETWORK",
"baseSeverity": "HIGH",
"valueDensity": "NOT_DEFINED",
"vectorString": "CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:L/VA:N/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",
"exploitMaturity": "NOT_DEFINED",
"providerUrgency": "NOT_DEFINED",
"userInteraction": "NONE",
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"attackRequirements": "PRESENT",
"privilegesRequired": "NONE",
"subIntegrityImpact": "NONE",
"vulnIntegrityImpact": "LOW",
"integrityRequirement": "NOT_DEFINED",
"modifiedAttackVector": "NOT_DEFINED",
"subAvailabilityImpact": "NONE",
"vulnAvailabilityImpact": "NONE",
"availabilityRequirement": "NOT_DEFINED",
"modifiedUserInteraction": "NOT_DEFINED",
"modifiedAttackComplexity": "NOT_DEFINED",
"subConfidentialityImpact": "NONE",
"vulnConfidentialityImpact": "HIGH",
"confidentialityRequirement": "NOT_DEFINED",
"modifiedAttackRequirements": "NOT_DEFINED",
"modifiedPrivilegesRequired": "NOT_DEFINED",
"modifiedSubIntegrityImpact": "NOT_DEFINED",
"modifiedVulnIntegrityImpact": "NOT_DEFINED",
"vulnerabilityResponseEffort": "NOT_DEFINED",
"modifiedSubAvailabilityImpact": "NOT_DEFINED",
"modifiedVulnAvailabilityImpact": "NOT_DEFINED",
"modifiedSubConfidentialityImpact": "NOT_DEFINED",
"modifiedVulnConfidentialityImpact": "NOT_DEFINED"
}
}
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},
"affected": [
{
"source": "disclosure@vulncheck.com",
"affectedData": [
{
"repo": "https://github.com/gravitl/netmaker",
"vendor": "gravitl",
"product": "netmaker",
"versions": [
{
"status": "affected",
"version": "0",
"versionType": "semver",
"lessThanOrEqual": "1.6.0"
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],
"packageURL": "pkg:github/gravitl/netmaker",
"collectionURL": "https://github.com/gravitl/netmaker",
"defaultStatus": "unaffected"
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"published": "2026-08-26T16:16:46.310",
"references": [
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"source": "disclosure@vulncheck.com"
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{
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"source": "disclosure@vulncheck.com"
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"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0"
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"vulnStatus": "Deferred",
"weaknesses": [
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"description": [
{
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"value": "CWE-295"
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],
"descriptions": [
{
"lang": "en",
"value": "Netmaker disables certificate verification on the connection to the configured mail server. The sender in pro/email/smtp.go assigns a TLS configuration whose skip-verify field is set to true unconditionally, directly beneath a comment stating that the setting should be false in production. No configuration value governs it and no code path restores verification, so the client accepts any certificate the mail server presents, including one an interposing party supplies. Mail that Netmaker sends over that connection includes password-reset messages carrying single-use tokens and user invitations carrying enrolment links, so a party positioned on the path between the server and its mail relay can read those messages in transit and use a captured reset token before the intended recipient does. The setting is absent from the development branch but present in the latest release."
}
],
"lastModified": "2026-09-24T20:43:32.537",
"sourceIdentifier": "disclosure@vulncheck.com"
}